sign in sign up
<<
Home , Pipotiazine

The prescribing of psychotropic drugs in services in Trinidad

Shelley Moore,1 Lazara K. Montane Jaime,1 Hari Maharajh,2 Indar Ramtahal,2 Sandra Reid,1 Feroza Sircar Ramsewak,1 and Mala Maharaj 2

ABSTRACT Objective. To describe, analyze, and interpret patterns of psychotropic drug prescribing in new psychiatric patients attending psychiatric outpatient clinics in the Caribbean island of Trinidad. Design and Methods. This was a cross-sectional study of psychotropic drug prescribing by psychiatrists for 132 new psychiatric outpatients who were seen at the outpatient clinics surveyed and who were entering the mental health system during the period of research, No- vember 1998 through February 1999. Results. A single patient could be prescribed more than one psychotropic drug. Antide- pressant drugs were the class of psychotropic drugs most prescribed (79 of 132 patients, 59.8%), followed by drugs (67 of 132 patients, 50.8%). (TCAs) were the antidepressants most prescribed (58 of the 79 patients), mainly (53 of the 58). was the only selective reuptake inhibitor (SSRI) prescribed (21 of the 79 patients prescribed antidepressants). Of the 67 patients receiving antipsychotic drugs, accounted for 41 of those 67, including (14 of the 41) and (13 of the 41). The individual antipsychotic most prescribed was (21 of the 67 patients). Anticholinergic drugs were prescribed to 20 of the 132 patients (15.1%). Eighty-three of the patients were prescribed more than one drug concomitantly (either more than one psychotropic or a combination of psychotropic(s) and nonpsychotropic(s)). Prescrip- tion by ethnicity, age, and gender coincided with the morbidity rates encountered in these pa- tients. The prescribing of SSRIs to persons of African or East Indian ethnicity was signifi- cantly lower than it was for persons of mixed heritage. Conclusions. The prescription patterns of psychotropic drugs in Trinidad revealed the psy- chiatrists’ preferences for traditional psychotropic drugs, the moderate use of anticholinergic drugs, and polypharmacy in some cases, with probable predisposition to adverse drug reac- tions. Given our results and based on the evaluation of individual patients, consideration should be given to a broader use of the newer antidepressants (SSRIs) and . Un- less justified, polypharmacy should be avoided.

Key words Psychotropic drugs, drug therapy, drug utilization, mental disorders, Trinidad and Tobago.

1 The University of the West Indies, St. Augustine, The rapidly expanding field of psy- exposed to newly introduced drugs Trinidad and Tobago. Send correspondence to: L.K. Montane Jaime, Pharmacology Unit, Faculty chopharmacology is challenging the that are claimed to be safer and more of Medical Sciences, The University of the West traditional concepts of psychiatric efficacious. Indies, Trinidad and Tobago; Fax/Phone: (868) treatments, and research is constantly Appropriate pharmacotherapy is 663-8613; e-mail: [email protected] 2 St. Ann’s Mental Hospital, Port-of-Spain, Trinidad seeking new and improved drugs to best achieved when the selection of a and Tobago. treat psychiatric disorders (1). In this drug and its dosage regimen is based way, psychiatrists are continuously on patient-specific factors. This pro-

Rev Panam Salud Publica/Pan Am J Public Health 12(3), 2002 207 cess must include taking complete All the data for our study were gath- great potential harm to the patient, current-drug and coexisting-disease ered by one of the researchers (S.M.), that occur frequently, and that are well histories in order to avoid possible who was present during the interviews documented. Moderately clinically sig- drug-drug interactions and adverse that the clinic psychiatrists conducted nificant interactions are those that are effects. In addition, socioeconomic and with all of the psychiatric patients at- of moderate potential harm, that do demographic factors must be taken tending one of the clinics for the first not occur as frequently as the previous into consideration in order to ensure time. The data were collected from 10 group, and that are not so completely patient compliance and success of November 1998 through 12 February documented (3). therapy. Besides rational considera- 1999. Our study only included patients tions, the use of psychotropic drugs 15 years and over since patients under may also be determined by social, psy- 15 years of age are not treated in the Statistical analysis chological, and cultural motives that outpatient clinics but are instead re- can shape the therapeutic behavior of ferred to Child Guidance services. We entered and analyzed our data psychiatrists as well as the drug pref- The information collected included using Epi Info version 6.02 computer erences of patients (2). sociodemographic characteristics such software (Centers for Disease Control Before this study, no researchers as age, gender, ethnicity, educational and Prevention, Atlanta, Georgia, had looked at these various psycho- level, and occupation. “Ethnicity” was United States of America). The chi- pharmacology issues in the Caribbean determined on the basis of the patient square test was used to find any dif- island of Trinidad. Our objective was having at least three of four grandpar- ferences in the use of the various to describe, analyze, and interpret pat- ents from the same ethnic group. Toxic psychotropic drugs by ethnicity, age terns of psychotropic drug prescribing habits (such as smoking and illicit group, or gender. Age was arranged in new psychiatric patients who were drug use) and coexisting diseases were in four groups: 15–19, 20–39, 40–59, attending psychiatric outpatient clin- also recorded. Drug information in- and 60+ years. The differences were ics in Trinidad. volved all drugs indicated for the psy- considered statistically significant when chiatric disorder as well as for any P < 0.05. other medical reason. Immediately MATERIALS AND METHODS after the interview, the researcher re- viewed the medical notes written by RESULTS We performed a cross-sectional sur- the psychiatrist in order to ensure that vey of psychotropic drug-prescribing the information gathered was accu- A total of 168 new psychiatric pa- practices in new patients attending rate. In addition, to check on informa- tients attended the seven psychiatric seven mental health outpatient clinics tion about any other drugs already outpatient clinics during the period of in Trinidad. Trinidad is the southern- being taken that the psychiatrist had research. Out of those 168, 36 patients most island of the Lesser Antilles. It is not asked about, the researcher briefly were excluded, leaving 132 patients in also the larger and more-populous of interviewed the patient after the psy- our sample. Some of the 168 patients the two islands that make up the coun- chiatrist’s interview and recorded any were eliminated due to age (i.e., less try of Trinidad and Tobago. The total additional information provided. than 15 years old). Others were ex- population of the country is around All the patients were able to answer cluded for being recommended for 1.3 million, with some 96% of these the questions that the psychiatrist hospitalization and treatment as inpa- persons living in Trinidad. Trinidad asked. In addition, the family mem- tients, rather than as outpatients who has a multiethnic society, mainly com- bers of some patients were present and would be prescribed at the posed of people of African heritage could verify the information that the initial psychiatric assessment. (39.6%) or of East Indian heritage patient had given. No patient refused (40.3%). The remainder of the popu- to answer any of the questions. lation is of White, Chinese, or mixed The lists of psychotropic drugs Patient characteristics ancestry. available during the period of research The seven outpatient clinics studied were obtained from the head pharma- Table 1 shows the distribution of the are part of the public health care sys- cist of each of the pharmacies from different sociodemographic charac- tem in Trinidad, which provides care the seven clinics studied. We only con- teristics of the 132 patients in the stud- at no cost to the patients. There are sidered clinically significant drug ied population. By ethnicity, the single also private clinics with pharmacy fa- interactions (3). The classification of largest group were persons of East cilities as well as private pharmacies, drug-drug interactions was based on: Indian ancestry. The largest group by but these are not free of charge. All a) potential harm to the patient, b) fre- age were those from 20 to 39 years old. drugs are available in the private sec- quency and predictability of occur- Women outnumbered men by a wide tor, but only those subsidized by the rence, and c) degree and quality of margin. government are available in the public documentation. Highly clinically sig- With respect to marital status, the system. nificant interactions refer to those of studied population had an almost

208 Moore et al. • The prescribing of psychotropic drugs in mental health services in Trinidad TABLE 1. Sociodemographic characteristics were given more than one diagnosis, serotonin reuptake inhibitors (SSRIs) of 132 new psychiatric patients in the men- that is, a major diagnosis and a coex- to 21 patients. Of the 58 TCA prescrip- tal health services of Trinidad, 1998Ð1999 isting condition.) and tions, 53 of them were for amitrip- other related disorders (29 of 149, or tyline, followed by (3 Characteristic No. % 19.5%) were the next most frequent di- prescriptions) and and Ethnic group agnoses, mainly in patients of African (1 prescription each). The East Indian 60 45.5 ancestry, while anxiety disorders rep- only SSRI prescribed was fluoxetine. African 39 29.5 resented 10.1% (15 of 149). Substance- Of the antipsychotics prescribed (67 Mixed 33 25.0 Age group (years) related disorders accounted for 3.4% patients), phenothiazines accounted 15–19 13 9.8 (5 of 149); these were mainly addic- for 41 of the 67 (61.2%). The main phe- 20–39 53 40.2 tions to or illegal drugs. The nothiazines prescribed were trifluo- 40–59 39 29.5 category of “others” (29 diagnoses) in- (14 of the 41 patients) and 60+ 27 20.5 cluded diagnoses with small numbers thioridazine (13 of the 41). These two Gender Male 51 38.6 of patients that were therefore grouped were followed by (6 of Female 81 61.4 for better statistical analysis. the 41), pipotiazine palmitate depot in- Marital status jection (5 of the 41), and Married 48 36.4 decanoate depot injection (3 of the 41). Single 51 38.6 Divorced 3 2.3 Coexisting diseases Interestingly, sulpiride (21 of the 67 Widowed 13 9.8 patients, or 31.3%) was the individual Separated 9 6.8 While some of the patients presented antipsychotic most prescribed, and Common-law 8 6.1 with no other medical illnesses, the was prescribed to only 3 Educational level overall number of coexisting disorders, of the 67 patients (4.5%). No schooling 8 6.1 Primary 70 53.0 159, was higher than the total number For the , there ap- Secondary 43 32.6 of patients in the study because some peared to be no single agent more pre- Tertiary 7 5.3 patients had more than one diagnosis scribed than any other. Othera 4 3.0 of a coexisting disorder. Cardiovascu- Benztropine was prescribed to 13 of a “Other” = special schools (e.g., school for the physically lar disorders (30 of 159 diagnoses, or the 132 patients (9.8%) and trihexy- challenged). 18.9%) were the most prevalent coex- phenidyl to 7 of the 132 (5.3%). isting illness encountered, with hyper- tension representing 60.0% (18 of 30) of this number. Endocrine disorders (17 Concomitant drug use of 159, or 10.7%) were the next most even distribution between patients prevalent medical complaint, with dia- Out of the 132 patients, there were who were married (36.4%) and those betes mellitus accounting for 12 of the 127 for whom the data were complete who were single (38.6%). Most of the 17 and hypothyroidism accounting for enough to allow us to access concomi- patients (73.5%) were unemployed. the remaining 5 of the 17. Other ill- tant drug use. Of those 127, 44 were Most of the patients had completed nesses were grouped under the cate- using only one drug, that is, just a psy- primary or secondary education (53.0% gory of “others” and accounted for chotropic drug. The other 83 patients and 32.6%, respectively). 25.2% (40 of 159) of the diagnoses of were using two or more drugs, either coexisting disorders. more than one psychotropic or a com- bination of psychotropic(s) and non- Psychiatric diagnoses psychotropic(s). Of these 83 patients, Psychotropic drug use 63 of them were using either two or All the clinic psychiatric consultants three drugs concomitantly, 17 of them in the study said that to diagnose their A single patient could be prescribed were using four or five drugs, and 3 of patients they used the Diagnostic and more than one psychotropic drug. An- them were using six or more drugs. Statistical Manual of Mental Disorders, tidepressant drugs were the class of Out of this group of patients using Fourth Edition (DSM-IV), published by psychotropic drugs most prescribed two or more drugs concomitantly, 51 the American Psychiatric Association. (79 of 132 patients, or 59.8%), followed of them were using nonpsychotropic Mood disorders represented 47.7% (71 by antipsychotic drugs (67 of 132 pa- drugs. Of these 51, 41 of them were of 149) of all diagnoses, with major tients, 50.8%). Benzodiazepines were using drugs prescribed by another depression being the most frequent, prescribed to 9.1% of the patients (12 physician, that is, not the psychiatrist especially in patients of East Indian of 132), while the anticholinergic drugs at the clinic. In addition, 15 of the 51 ancestry. (The overall number of psy- represented 15.2% (20 of 132). were self-medicating, according to chiatric diagnoses, 149, was higher Among the drugs, their self-reporting. than the number of patients in the tricyclic antidepressants (TCAs) were In terms of the groups of nonpsy- study because some of the 132 patients prescribed to 58 patients, and selective chotropic drugs used concomitantly,

Rev Panam Salud Publica/Pan Am J Public Health 12(3), 2002 209 TABLE 2. Use of psychotropic drugs, by ethnicity, among 132 new psychiatric patients in the mental health services of Trinidad, 1998-Ð1999

East Indian African Mixed Psychotropic (n = 60) (n = 39) (n = 33) drug No. % No. % No. % P value

Antidepressants 0.005a TCAs 34 56.7 16 41.0 8 24.2 SSRIs 9 15.0 2 5.1 10 30.3 Antipsychotics 0.390 Phenothiazines 11 18.3 15 38.4 15 45.5 Others 11 18.3 10 25.6 5 15.2 Anxiolytics NAb Benzodiazepines 5 8.3 4 10.3 3 9.1 Anticholinergics 0.970 2 3.3 3 7.7 2 6.1 Benztropine 5 8.3 4 10.3 4 12.1

a Statistically significant. b A P value was not computed for anxiolytics since only one group (benzodiazepines) was used in the study.

the most common were antihyperten- Age group. There were no statistically males there was only a small differ- sives, followed by antidiabetics and significant differences in the prescrib- ence. The rate of pre- nonsteroidal anti-inflammatory drugs. ing of psychotropic drugs by age scribing for females was about twice group (Table 3). However, there was a the rate for males. Conversely, anti- trend of prescribing TCAs at a higher cholinergic prescriptions were about Psychotropic drug utilization and rate than SSRIs for those 40–59 and twice as common for men as they were sociodemographic characteristics those 60 and older. for women.

Ethnicity. Table 2 shows the patterns Gender. Female patients were pre- found in terms of the prescribing of scribed antidepressants more than they Smoking psychotropic drugs by ethnicity. Only were antipsychotics, while the reverse one difference was statistically signif- was true for males (Table 4). TCAs Of the 132 patients, 99 of them icant; that was for the prescribing of were prescribed much more frequently (75.0%) were nonsmokers, and 23 of antidepressants. Persons of African or than were SSRIs, to both males and fe- the 132 (17.4%) were reportedly smok- East Indian descent were prescribed males. For males, the prescribing of ing 24 or more cigarettes per day. Of SSRIs less often than were persons of phenothiazines was much greater than these 23 heavy smokers, 14 of them mixed ethnicity. that of other antipsychotics, but for fe- were given antidepressant prescrip-

TABLE 3. Prescribing of psychotropic drugs by age (years) among 132 new psychiatric patients in the mental health services of Trinidad, 1998Ð1999

15–19 20–39 40–59 60+ (n = 13) (n = 53 (n = 39) (n = 27) Psychotropic Drugs No. % No. % No. % No. % P value

Antidepressants 0.236 TCAs 2 15.4 20 37.7 23 59.0 13 48.1 SSRIs 2 15.4 11 20.8 6 15.4 2 7.4 Antipsychotics 0.206 Phenothiazines 3 23.1 22 41.5 6 15.4 10 37.0 Others 5 38.5 9 17.0 7 17.9 5 18.5 Anxiolytics a Benzodiazepines 0 0.0 7 13.2 4 10.3 1 3.7 Anticholinergics b Trihexyphenidyl 1 7.7 5 9.4 1 2.6 0 0.0 Benztropine 3 23.1 5 9.4 4 10.3 1 3.7 a A P value was not computed for anxiolytics since only one group (benzodiazepines) was used in the study. b A P value was not calculated for the anticholinergics because one of the cell values was 0.

210 Moore et al. • The prescribing of psychotropic drugs in mental health services in Trinidad TABLE 4. Prescribing of psychotropic drugs by gender among 132 new psychiatric patients comfortable with prescribing the tradi- in the mental health services of Trinidad, 1998Ð1999 tional agents. Both SSRIs and TCAs have been re- Male Female (n = 51) (n = 81) ported as having similar onset of ac- tion and therapeutic efficacy. The ben- Psychotropic drugs No. % No. % P value efit with SSRIs seems to be the lower Antidepressants 0.294 incidence of side effects (lack of seda- TCAs 18 35.3 40 49.4 tive, anticholinergic, and hypotensive SSRIs 4 7.8 17 21.0 effects); the wider therapeutic index, Antipsychotics 0.148 Phenothiazines 23 45.1 18 22.2 making them safer in terms of possible Others 10 19.6 16 19.8 overdose; and the once-daily dosing, Anxiolytics a which may improve patient compli- Benzodiazepines 4 7.8 8 15.7 ance (4–6). The prescription of SSRIs Anticholinergics 0.418 was significantly lower than that of Trihexyphenidyl 5 9.8 2 2.5 Benztropine 6 11.8 7 8.6 TCAs in patients of African ancestry as compared with persons of East Indian a A P value was not computed for anxiolytics since only one group (benzodiazepines) was used in the study. heritage. Some psychiatrists in the Caribbean believe that fluoxetine is less efficacious in patients of African heritage; this may explain the lower use of SSRIs in patients of this ethnic tions; 8 received TCAs and 6 received condition of the patient and the need group in our sample. SSRIs. for patient-specific treatment. Amitriptyline was the TCA most Antipsychotic prescriptions were given Our study found that antidepres- prescribed, although 6 of the 7 outpa- to 13 of the 23 heavy smokers. In addi- sant drugs were the most-prescribed tient clinic pharmacies had imipra- tion, benzodiazepine was prescribed psychotropic drug, followed by an- mine available during the period of re- to 5 of the 23. tipsychotic drugs. This is in accor- search. Fluoxetine was the only SSRI Anticholinergics were mostly pre- dance with the fact that depression prescribed, as it is the only SSRI avail- scribed to nonsmokers. and schizophrenia had the highest re- able in the clinics. There was a trend of ported morbidity rates among these prescribing TCAs more often to pa- patients. Patients of East Indian ances- tients aged 40–59 and 60+. This occurs Drug interactions try were prescribed significantly more despite the recommendation of SSRIs antidepressants since depression was for elderly people because of the in- We identified 20 potential drug-drug more frequently diagnosed in this creased potential for significant clini- interactions among the 83 patients who ethnic group. Patients of African an- cal problems with the anticholinergic were prescribed more than one drug cestry received more antipsychotics side effects of TCAs (7, 8). concomitantly. Most of these potential since they were more frequently diag- There is also a clear preference by interactions were of moderate clinical nosed with schizophrenia. Females pre- psychiatrists in Trinidad for pheno- significance. Cases of psychotropic senting to the clinics were diagnosed thiazines as compared to other types prescriptions for patients with coexist- more frequently with depression and of drugs. Al- ing diseases were found, which could males with schizophrenia, which also though all typical antipsychotics are predispose to adverse reactions. These explains why antidepressants rather equally effective, they differ in their patients require close monitoring or than antipsychotics were prescribed propensity to induce side effects (9). use of an alternative drug. more for females. Haloperidol produces less sedation, Psychiatrists in Trinidad are still fewer anticholinergic effects, and fewer prescribing TCAs over SSRIs for their cardiovascular effects but at the cost DISCUSSION patients. This may be due to three fac- of a higher incidence of extrapyrami- tors: 1) the erratic and inconsistent dal effects. Although no consensus is The study of psychotropic drug pre- availability of SSRIs in some clinics available, many feel that the side-effect scription in new patients is important (the medication does not always reach profile of haloperidol is easier for the since the initial treatment selected is the public clinics on a timely basis), clinician to manage and is better toler- of significance for therapeutic success 2) the higher cost of SSRIs (but as these ated by the patient. When analyzing and patient compliance. Therefore, drugs are provided free of charge to individual drugs, we found that sul- treatment should be carefully chosen the patients in the clinics, the limiting piride was the individual antipsy- by weighing the relative risks and ben- factor could be the cost of importing chotic drug most used. While the risk efits of different therapeutic regimens and distributing them), and 3) psychi- of extrapyramidal side effects is as on the basis of an evaluation of the atrists are more accustomed to or more great as with more-potent drugs, psy-

Rev Panam Salud Publica/Pan Am J Public Health 12(3), 2002 211 chiatrists in Trinidad have commonly these moderate ones are to be ignored. prazolam and to decrease the alprazo- found that sulpiride is well tolerated. Other research has found that interac- lam elimination rate constant (17, 18). Antipsychotic depot injections are tions are likely to occur in some pa- The interaction between carba- usually not recommended for patients tients; therefore, the potential risk to mazepine and fluoxetine (combined in at the first presentation. However, if the patient has to be assessed and ap- one patient in our study) has been the patient lacks insight into the illness propriate action taken (3). rated as “potentially hazardous,” and and will clearly be noncompliant, it The use of polypsychopharmacy in combined administration of the drugs may be prescribed. This was done for our patients was not small. Antipsy- involved should be “avoided” or only one-fifth of the patients for whom an- chotic and antidepressant users were undertaken with caution and appro- tipsychotics were prescribed. more frequently subjected to polypsy- priate monitoring (19, 20). The seizure- While the prescription of classes of chopharmacy than were others. The convulsive threshold is lowered by antipsychotics was not significantly most prevalent combinations were this combination, and also the plasma different among the ethnic groups, antipsychotic-antipsychotic and anti- concentration of could there was a trend to prescribe pheno- depressant-anxiolytic. It has been re- be increased and resultant adverse ef- thiazines more frequently to patients ported that two antipsychotics are no fects could occur. of mixed ethnicity. Sulpiride and ha- more effective than a single agent (10, Three patients received TCAs while loperidol were the individual drugs 11). However, the incidence of side having concomitant treatment with prescribed at a higher rate than any effects may increase, including ex- . This beta-blocker de- single in patients 20–39 trapyramidal effects, and thus the pos- creases blood flow to the liver, so me- years old. sible additional need for anticholin- tabolism of TCAs may decrease, lead- Among the different ergics to counteract these effects. ing to accumulation of TCAs and available to treat acute extrapyram- Additionally, since this is the patient’s possible toxicity. The mechanism is idal side effects, benztropine and first visit to the clinic, a trial with a sin- not totally understood (21). TCAs also trihexyphenidyl were used. Given the gle drug is recommended, and further reduce the effects of sublingual ni- high rate of acute extrapyramidal evaluations would determine the need trates due to the predisposition to dry- side effects among patients receiv- for any additional steps. ness of the mouth. This is of moderate ing antipsychotic medications, espe- Combinations of antidepressants are clinical significance, and the addition cially the elderly, the short-term pro- sometimes used, although the benefit of TCAs to the therapy of patients phylactic use of anticholinergic drugs to be derived from polypharmacy has using nitrates should be carefully as- may be considered. The benefit of not been demonstrated in blinded sessed and an alternative chosen if this approach has been demonstrated studies and is likely to be outweighed possible (22). We found this combina- in several studies (9). The risk is that by the increased risk of the combined tion in four patients in our study. some patients may be treated unnec- side effects (12). One combination we The sedative and anticholinergic ef- essarily. The data in our study show found was fluoxetine and a TCA (five fects of either TCAs or phenothiazines that the use of anticholinergic agents patients). It has been reported that flu- may be prolonged and intensified with was reserved for only a small num- oxetine may lead to a more rapid concomitant use due to the inhibition ber of cases. The number of patients down-regulation of postsynaptic beta- of the metabolism of both drugs (four who presented to the clinics with adrenergic receptors, thus possibly patients in our study). The risk of sei- anxiety disorders was small, hence contributing to a faster onset of action zures may be increased by lowering the small number of prescriptions of of TCAs. However, fluoxetine impairs the seizure threshold, so drugs should benzodiazepines. the hepatic oxidative metabolism of be added or withdrawn with caution. Comorbid psychiatric conditions or TCAs, which can result in an increase Psychotic depressions respond well to coexisting medical diseases are usu- of 100%–300% in TCA plasma concen- a combination of TCAs and antipsy- ally found in psychiatric patients, tration as well as an increase in ad- chotic agents, but both agents should hence the need to use more than one verse effects, including seizures and be initially administered at lower doses drug. If more than one drug is chosen, delirium (12–15). Fluoxetine was also and increased as is clinically indicated. it is recommended that the patient be combined with benzodiazepines in The risk of neuroleptic malignant syn- closely monitored for adverse effects. two of the patients in our study. Flu- drome may also be increased (23). We found that some patients in our oxetine may decrease the metabolism The mechanism of the interaction of study were prescribed combinations of benzodiazepines through competi- selected phenothiazines and selected of drugs that could lead to drug-drug tive inhibition at the cytochrome P450 beta-blockers (combined in one patient interactions, in some cases of moder- site, resulting in increased levels of in our study) is unknown; however, in- ate clinical significance but in others of benzodiazepines and an increase in terference with metabolism is a likely highly clinical significance. Although their clinical effects (16). Fluoxetine possibility. There may be increased moderately significant interactions are has also been shown to increase the plasma levels, with resultant enhanced less of a threat than highly significant maximum concentration, the area pharmacological response of each or interactions, it does not mean that under the curve, and the half-life of al- both drugs as well as increased risk of

212 Moore et al. • The prescribing of psychotropic drugs in mental health services in Trinidad toxicity. If both drugs are adminis- idad, concomitant drug and cigarette done since the initial treatment se- tered, the dosages should be adjusted use need to be considered. lected is essential for therapeutic suc- as needed based on the patient’s re- cess and patient compliance. We en- sponse. Serum chlorpromazine or thio- courage a broader use of the newer ridazine concentrations may decrease CONCLUSIONS antidepressants (SSRIs) and antipsy- if beta-blocker therapy is discontinued. chotics, on the basis of an evaluation of Similarly, plasma concentrations of the This research study was the first that the condition of the patient. Indepen- beta-blockers may decrease if chlorpro- has been done with the aim of reveal- dent of which psychotropic drug is mazine or thioridazine is discontinued ing the pattern of psychotropic drug used, the presence of concomitant dis- (24, 25). prescribing in psychiatric outpatients orders that require pharmacological The concomitant drug use and toxic in Trinidad. We found psychiatrists’ treatment should be considered in habits of the patients also have to be preferences for traditional psycho- order to reduce adverse drug interac- considered during the psychiatric in- tropic drugs, including TCAs and phe- tions. Unless justified, polypharmacy terview and before choosing any drug. nothiazines; moderate use of anti- should be avoided. Many psychiatrists did not take a full cholinergic drugs; polypharmacy in We hope that this knowledge will be drug history from the patients in our some cases, with probable predisposi- helpful in improving future prescrib- study, including that of toxic habits. tion to adverse drug reactions; and ing practices in Trinidad. Many psychotropics are metabolized doctors sometimes not asking about by the liver, so smokers are at risk of concomitant drug use. Prescription by having lower levels of the psychotropic ethnicity, age, and gender coincided Acknowledgement. Many thanks agent by induction of hepatic microso- with the morbidity rate encountered in go to Dr. D. Simeon, a statistician with mal enzymes by (26). As the these patients. the Department of Community Health ability to monitor patient plasma levels Prescription of psychotropic drugs of The University of the West Indies. of drugs remains unavailable in Trin- in new patients should be carefully

REFERENCES

1. Pincus HA, Tanielian TL, Marcus SC, Olfson ferential treatment. Am J Psychiatry 1970; 19. Spina E, Avenoso A, Pollicino AM, Capurti M, Zarin DA, Thompson J, et al. Prescribing 126(11):1647–1651. AP, Fazio A, Pisani F. Carbamazepine co- trends in psychotropic medications: primary 11. Rosholm JU, Hallas J, Gram LF. Concurrent administration with fluoxetine or fluvoxam- care, psychiatry and other medical specialties. use of more than one major psychotropic drug ine. Ther Drug Monit 1993;15(3):247–250. JAMA 1998;279(7): 526–531. (polypsychopharmacy) in out-patients—a 20. Grimsley SR, Jann MW, Carter JG, D’Mello 2. Voirol P, Robert PA, Meister P, Oros L, Bau- prescription database study. Br J Clin Phar- AP, D’Souza MJ. Increased carbamazepine mann P. Psychotropic drug prescription in a macol 1994;37(6):533–538. plasma concentrations after fluoxetine coad- psychiatric university hospital. Psychopsychi- 12. Vaughan DA. Interaction of fluoxetine with ministration. Clin Pharmacol Ther 1991;50(1): atry 1999;32(1):29–37. tricyclic antidepressants. Am J Psychiatry 10–15. 3. Zucchero FJ, Hogan MJ. Evaluations of drug 1988;145(11):1478. 21. Stockley IH. Drug interactions. 3rd edition. interactions. St. Louis, Missouri, United States 13. Preskorn SH, Beber JH, Faul JC, Hirschfeld London: Blackwell Scientific Publications; of America: PDS Publishing Co.; 1990. RM. Serious adverse effects of combining flu- 1991. 4. Rickels K, Schweizer E. Clinical overview of oxetine and tricyclic antidepressants. Am J 22. British Medical Association and Royal Phar- serotonin reuptake inhibitors. J Clin Psychia- Psychiatry 1990;147(4):532. maceutical Society of Great Britain. British try 1990;51 Suppl B:9–12. 14. Westermeyer J. Fluoxetine-induced toxicity: National Formulary (BNF). London: BMA 5. Dunbar GC, Cohn JB, Fabre LF, Feighner JP, extent and duration. J Clin Pharmacol 1991; and RPSGB; 1998. Fieve RR, Mendels J, et al. A comparison of 31(4):388–392. 23. Davies DM. Textbook of adverse drug reac- , imipramine and placebo in de- 15. Bergstrom RF, Peyton AL, Lemberger L. tions. 4th edition. New York: Oxford Univer- pressed out-patients. Br J Psychiatry 1991;159: Quantification and mechanism of the fluoxe- sity Press; 1991. 394–398. tine and interaction. 24. Miller FA, Rampling D. Adverse effects of 6. Montgomery SA. Sertraline in the prevention Clin Pharmacol Ther 1992;51(3):239–248. combined propranolol and chlorpromazine of depression [letter]. Br J Psychiatry 1992;161: 16. Lemberger L, Rowe H, Bosomworth JC, Ten- therapy. Am J Psychiatry 1982;139(9):1198– 271–272. barge JB, Bergstrom RF. The effect of fluoxe- 1199. 7. Montgomery SA. Efficacy and safety of the se- tine on the pharmacokinetics and psychomo- 25. Silver JM, Yudofsky SC, Kogan M, Katz BL. lective serotonin reuptake inhibitors in treat- tor responses of diazepam. Clin Pharmacol Elevation of thioridazine plasma levels by ing depression in elderly patients. Int Clin Ther 1988;43(4):412–419. propranolol. Am J Psychiatry 1986;143(10): Psychopharmacol 1998;13 Suppl 5:S49–54. 17. Lasher TA, Fleishaker JC, Steenwyk RC, Antal 1290–1292. 8. DasGupta K. Treatment of depression in el- EJ. Pharmacokinetic-pharmacodynamic eval- 26. Kelly C, McCreadie RG. Smoking habits, cur- derly patients: recent advances. Arch Fam uation of the combined administration of al- rent symptoms, and premorbid characteristics Med 1998;7(3):274–280. prazolam and fluoxetine. Psychopharmacol- of schizophrenic patients in Nithsdale, Scot- 9. American Psychiatry Association. Practice ogy (Berl) 1991;104(3):323–327. land. Am J Psychiatry 1999;156(11):1751–1757. guideline for the treatment of patients with 18. Greenblatt DJ, Preskorn SH, Cotreau MM, schizophrenia. Am J Psychiatry 1997;154:4. Horst WD, Harmatz JS. Fluoxetine impairs 10. Merlis S, Sheppard C, Collins L, Fiorentino D. clearance of alprazolam but not of clonaze- Manuscript received 16 August 2001. Revised version ac- Polypharmacy in psychiatry: patterns of dif- pam. Clin Pharmacol Ther 1992;52(5):479–486. cepted for publication 7 June 2002.

Rev Panam Salud Publica/Pan Am J Public Health 12(3), 2002 213 RESUMEN Objetivos. Describir, analizar e interpretar las características de la prescripción de psicotrópicos en pacientes nuevos que acudieron a las consultas externas de psiquia- tría en la isla caribeña de Trinidad. Prescripción de psicotrópicos Métodos. Se realizó un estudio transversal de los psicotrópicos prescritos por en los servicios de salud psiquiatras a 132 nuevos pacientes psiquiátricos ambulatorios que acudieron a con- mental de Trinidad sultas externas por primera vez entre noviembre de 1998 y febrero de 1999. Resultados. Algunos pacientes recibieron más de un psicotrópico. Los antidepre- sivos fueron los psicotrópicos recetados con mayor frecuencia (79 de los 132 pacientes, 59,8%), seguidos de los antipsicóticos (67/132; 50,8%). Los antidepresivos prescritos con mayor frecuencia fueron los tricíclicos (58/79; 73,4%), y en particular la amitrip- tilina (53/58; 91,4%). La fluoxetina fue el único inhibidor selectivo de la recaptación de serotonina (ISRS) que se recetó (21/79; 26,6%). De los 67 pacientes que recibieron an- tipsicóticos, a 41 (61,2%) se les recetaron fenotiazinas, entre ellas la trifluoperazina (14/41; 34,1%) y la tioridazina (13/41; 31,7%). El antipsicótico prescrito con más fre- cuencia fue la sulpirida (21/67; 31,3%). A 20 de los 132 pacientes (15,1%) se les rece- taron anticolinérgicos. A 83 (62,9%) se les prescribió más de un fármaco simultá- neamente: o bien más de un psicotrópico o una combinación de psicotrópicos y no psicotrópicos. La prescripción por etnia, edad y sexo coincidió con las tasas de mor- bilidad observadas en los diferentes grupos. La prescripción de ISRS a pacientes de origen africano o indio fue significativamente menos frecuente que a los de origen mixto. Conclusiones. Estos resultados muestran una preferencia de los psiquiatras de Trinidad por los psicotrópicos tradicionales, un uso moderado de los anticolinérgicos y, en algunos casos, el uso de la polifarmacia, que podría predisponer a la aparición de reacciones adversas graves. Teniendo en cuenta estos resultados y dependiendo de las circunstancias de cada paciente, se debería considerar un uso más amplio de los antidepresivos (ISRS) y antipsicóticos más recientes y evitar el uso de la polifarmacia,

Glosario de medicamentos: desarrollo, evaluación y uso Este libro no es solo una simple descripción de términos. Con el fin de facilitar al lector el uso de la literatura especializada en inglés, en él se ha incluido el equivalente, en ese idioma, de cada uno de los términos. El libro contiene, además, algunas advertencias en cuanto a las traducciones del inglés al español de términos relacionados con medicamentos, una hoja de instrucciones, una lista de abreviaturas, acrónimos, siglas, símbolos y sinónimos, así como un índice en inglés de los términos incluidos en el glosario. 1999 • 312 pp. ISBN 92 75 32305 4 Este glosario es de gran utilidad para los profesionales de la farmacología, de la medicina Código: OT 118• y de carreras afines que de una manera u otra se encuentran vinculados con organismos ofi- Precio: US$ 20.00/ US$ 15.00 en América ciales encargados de evaluar, registrar, seleccionar, y velar por el control de calidad de los Latina y el Caribe medicamentos, así como de investigar su uso.

Para ordenar: http://publications.paho.org; E-mail: [email protected]; Fax: (301) 209-9789; Tel: (301) 617-7806; (1-800) 472-3046 (U.S. solamente)

214 Moore et al. • The prescribing of psychotropic drugs in mental health services in Trinidad