Postgrad Med J7 1996; 72: 109-112 C) The Fellowship of Postgraduate Medicine, 1996 Postgrad Med J: first published as 10.1136/pgmj.72.844.109 on 1 February 1996. Downloaded from The risk of severe salicylate poisoning following the ingestion of topical medicaments or aspirin Thomas YK Chan Summary The main objective of this retrospective Apart from isolated reports of severe study was to assess the risk of severe salicylate salicylate poisoning after ingesting an poisoning amongst patients who had self- unusually large amount of a medicinal poisoned themselves with topical medicaments oil, there are no published data on the or aspirin tablets. threat arising from attempted suicide with topical medicaments containing Patients and methods methyl salicylate or wintergreen oil com- pared with aspirin tablets. In this retro- The Prince ofWales Hospital is the sole general spective study, the admission plasma teaching hospital in the New Territories East, salicylate concentrations and clinical Hong Kong, serving a population of about 1.2 presentations were compared in 80 sub- million in 1994. Also situated in this region are jects who had taken aspirin tablets two Vietnamese refugee camps. (n = 42) or topical medicaments (n = 38). From January 1991 to December 1993, all The proportions of subjects being symp- patients admitted to our general medical wards tomatic were similar in the two groups. with a history of salicylate ingestion were Although the admission plasma salicylate included in the study. They were identified concentrations were generally higher in from our previous studies of the pattern of subjects who had ingested aspirin tablets, acute poisoning4'6'7 or the registry of requests the two highest readings (4.3 and 3.5 for plasma salicylate measurements. Patients mmol/l) belonged to two of the subjects who had taken unknown analgesics/antipyr- who had taken topical medicaments. etics but with undetectable plasma salicylate Because of its liquid, concentrated form concentrations (< 0.1 mmol/ 1) were excluded. and lipid solubility, methyl salicylate The hospital records of these patients were poses the threat of severe, rapid-onset reviewed. Demographic data and information salicylate poisoning. The toxic potential regarding agents used, clinical features, treat- oftopical medicaments containing meth- ment given and outcome were noted. The http://pmj.bmj.com/ yl salicylate or wintergreen oil should be identification of the agents responsible was fully appreciated by both physicians and based on the history from the patient/ the general public. witnesses, labelling on the containers and/or the clinical features. For patients who had Keywords: salicylate poisoning, poisoning, topical concomitantly taken more than one agent, only medicament, methyl salicylate, aspirin signs and symptoms that could be attributed to salicylates were considered. on September 29, 2021 by guest. Protected copyright. Salicylate poisoning remains a common prob- Results lem in many Western countries with an app- reciable morbidity and mortality." 2 This is due Eighty patients who had ingested various kinds largely to the ready availability of aspirin and of aspirin tablets (n = 42) or topical medica- the frequent occurrence of salicylates in unex- ments containing methyl salicylate or winterg- pected sources such as cold and allergy reen oil (n = 38) were studied. The main preparations, oil of wintergreen, rubefacients reasons for self-poisoning included emotional for rheumatism and ointments for psoriasis.3 upset, social crisis and physical illness. The more serious incidents in adults normally Psychiatric assessment indicated that three of occur following the ingestion of large doses of the patients who had ingested tablet formula- aspirin in its various formulations - solid, tions were suffering from anxiety and/or Department of Clinical soluble, sustained release and liquid prepara- depression. Pharmacology, The tions. As can be seen in table 1, most ofthe Chinese Chinese University of In Hong Kong, aspirin and other analgesics subjects included in this study had taken Hong Kong, Prince of accounted for 10-18% of the adult cases of aspirin tablets, whereas most ofthe Vietnamese Wales Hospital, self-poisoning admitted to the Prince of Wales subjects had taken topical medicaments. Sub- Shatin, New Hospital during 1988 to 1991.4 Topical jects who had taken aspirin tablets tended to Territories, Hong Kong medicaments containing wintergreen oil or present with mixed overdosage involving other TYK Chan methyl salicylate were involved in about half of drugs or chemicals. Six ofthe subjects from the the patients who were suspected to have topical medicament group went missing within Accepted 5 September 1995 ingested salicylates.5 48 hours of admission. The two groups were 110 Chan otherwise comparable with regard to age, time The plasma salicylate concentration in rela- lapsed between ingestion and admission to an tion to the time of ingestion is shown in the emergency department, the use of gastric figure. Twenty-four subjects were excluded Postgrad Med J: first published as 10.1136/pgmj.72.844.109 on 1 February 1996. Downloaded from lavage or ipecac, the proportion having symp- because the test was not requested (n = 1), the toms of salicylate poisoning and duration of time of ingestion was not known (n = 6) or hospital stay. The alleged amounts ofaspirin or plasma salicylate concentrations were below salicylates ingested by the two groups of subj- 0.1 mmol/1 (n = 17). In the 11 patients who ects are summarised in table 2. had two or more measurements (six had taken aspirin tablets), the highest plasma level was used for analysis. Subjects who had taken aspirin tablets tended to have higher plasma salicylate concentrations than subjects who had Table 1 Clinical details of 80 subjects who self-poisoned themselves taken topical medicaments, although the two with two different formulations of salicylates subjects with the highest levels belonged to the Tablets Topical medicament latter group. (n = 42) (n = 38) Urinary alkalinisation8 was considered neces- sary in the two patients with moderate to severe Men:women ratio 8:34 7:31 of after Chinese subjects 39 (93%) 4 (10%) symptoms salicylate poisoning inges- Vietnamese subjects 2 (5%) 34(90%) ting 30 'Anacin' tablets (plasma salicylate con- Age (years) 22 (15-80)* 22 (15-86)* Ingestion-admission intervals (h) 3 (0.5-48)* 3 (0.5- 16)* Mixed overdosage 27 (64%)** 10 (26%)t 5.0 Gastric lavage/ipecac 32(76%) 29(76%) Plasma salicylate levels (mmol/ 1) o 4.5 not requested 1 (2%) 0 E <0.1 4(10%) 13(34%) E 4.0 0.1-1.0 13 (31%) 18(48%) c 1.1-2.1 16(38%) 5 (13%) .° 3.5 1- ~~0 > 2.2 8 (19%) 2(5%) 3-0 Severity ofsalicylate poisoningtf c4 o no symptoms 17(40%) 13(34%) 0 0 mild 24 (58%) 24 (64%) 20O -8 °00 80 o moderate to severe 1 (2%) 1 (2%) Duration ofstay (days) 2 (1 -4)* 2 (1 -5)* 0 Outcome (%) C 1-5 found missing 0 6 (16%) _co discharge against medical advice 3(7%) 1(3%) 02.00 transferred to other units 2(5%) 1(3%) E<, 0-5 -o home 37 (88%) 30(79%) L 0 *Medians and ranges. **Other agents included paracetamol or paracetamol- 85 lo 15 2 30 35 40 45 50 containing drugs (n = 13), hypnotics (n = 7), alcohol (n = 7), Chinese proprietary Hours after ingestion medicines (n = 4), tricyclic antidepressants (n = 2), antacids (n = 2), and household products (n = 2). tOther agents included alcohol (n = 4), antibiotics (n = 3), Figure Plasma salicylate concentration in relation to paracetamol (n = 2), and household products (n = 2). ttSymptoms including nausea, the time ofingestion in 56 subjects who had taken http://pmj.bmj.com/ vomiting, tinnitus, deafness, sweating, hyperventilation and respiratory aspirin tablets (0, n = 36) or topical medicaments (0, alkalosis/metabolic acidosis. n = 20). Table 2 The alleged amounts of aspirin tablets or topical medicaments ingested by 80 subjects Dosageform Quantity on September 29, 2021 by guest. Protected copyright. Tabletformulations (n = 42) Cortal (n = 21) 10tab = 8; 11-20 = 11; > 21 = 1;NK = 1 Anacin (n = 8) 10 tab = 3*; 11 -20 = 2; > 21 = 2; NK = 1 Aspirin**(n =4) 10 tab = 1; > 21 = 1; NK = 2 Coricidin(n= 1) 11-20tab= 1 Excedrin (n= 1) 11 -20 tab = 1 Unspecified (n = 7) 11 -20 tab = 1; > 21 =2; NK= 4 Topical medicaments (n = 38) White Flower Medicine Oil (n = 22)t < 10 ml = 5; 11 -20 = 2; > 21 = 2; NK = 13 Red Flower Oil (n = 5) 11 -20 ml = 1; NK = 4 Axe Brand Universal Oil (n = 1) 11-20 ml = 1 Black Man Oil (n = 1) NK= 1 Unspecified medicated oils (n = 9) < 10 ml = 1; 11 -20 = 2; > 21 = 2; NK = 4 NK = not known. *One subject also took two aspirin tablets. **The strength of the tablet was not specified. tOne subject also took an unknown amount ofan unspecified medicated oil. Cortal (acetylsalicylic acid 500 mg, caffeine 30 mg), Anacin (aspirin 400 mg, caffeine 32 mg), Coricidin (chlorpheniramine 2mg, acetylsalicylic acid 388.8 mg, caffeine 32.4 mg), Excedrin (acetaminophen 250 mg, aspirin 250 mg, caffeine 65 mg). White Flower Medicine Oil (wintergreen oil 40%, menthol crystal 30%, eucalyptus oil 18%, camphor 6%, lavender oil 6%), Red Flower Oil (wintergreen oil 67%, turpentine oil 22%, cinnamic aldehyde 5%, cinnamon leaf oil 4%, citronella oil 2%), Axe Brand Universal Oil (methyl salicylate 15%, menthol crystals 20%, eucalyptus oil 15%, essential oil 12%, camphor 5%), Black Man Oil (wintergreen oil 28%, turpentine oil 70%, thymol crystal 1 %, citronella oil 1 %). Salicylate poisoning 111 centration 1.9 mmol/l seven hours post- fatal,"4 although the lethal dose in adults is ingestion) or an unknown amount of 'Red estimated at 30 m1.'4"15 Ingestion of 100 ml of Flower Oil' (4.3 mmol/1 at 11.5 hours).