Oral Terbutaline in the Management of Pharmacologically Induced Prolonged Erection

Oral terbutaline in the management of pharmacologically induced prolonged erection

S Priyadarshi

Department of Urology, SMS Medical College & Hospital, Jaipur, India

Prolonged erection and priapism are common complications following intracavernosal injection of vasoactive agents in the management of erectile dysfunction. It is usually treated by intracorporeal drainage and irrigation with sympathomimetic agents. There is no established oral therapy . To study the effect of oral terbutaline on prolonged erection following intracavernosal injection of vasoactive agent, a controlled randomized study was done in 68 patients. Detumescence was achieved in 42 and 15% of the cases with oral terbutaline and placebo, respectively. Results of this study suggest that an initial trial with oral terbutaline for pharmacologically induced prolonged erection may be successful. International Journal of Impotence Research (2004) 16, 424–426. doi:10.1038/sj.ijir.3901180 Published online 4 March 2004

Keywords: priapism; prolonged erection; terbutaline

Introduction Materials and methods

There has been a resurgence of interest in the field of During the last 3 y, 500 men with erectile dysfunc- impotence among both patients and physicians with tion received intracorporeal injection of a bimix the development of various surgical and nonsurgical solution containing papaverine and chlorproma- therapies. Various vasoactive compounds as intra- zine, as part of their evaluation and treatment. The corporeal injections have been used in both the dosage ranged from 0.1 to 0.5 ml. Patients were diagnostic evaluation and treatment of impotence.1 completely evaluated to make a diagnosis regarding Pharmacologically induced erections have various the aetiology of erectile dysfunction. It included potential complications of which the most signifi- history, physical examination, urine analysis, serum cant is prolonged erection or priapism.2 The testosterone, prolactin blood biochemistry, pharma- incidence of prolonged erection ranges from 2 to cologic erection test and penile duplex ultrasono- 18% depending upon the type of agent and the graphy with pharmacologic stimulation in select amount of dose used.2 The standard therapy for patients. All patients were observed in the office such prolonged erection is drainage and irrigation of until full detumescence occurred. Those patients 3 1 the corporal bodies with sympathomimetic agents. with full erection persisting for more than 22 h were There is no established oral medication although then treated with oral medication, either terbutaline some recent reports have suggested that pseudoe- 5 mg or placebo (sodium bicarbonate) and observed phedrine and terbutaline may be effective in rever- for 15 min. An additional dosage of 5 mg was given if 4,5 sing such erections. This study was conducted to detumescence did not occur after 15 min and determine the efficacy of oral terbutaline in phar- 30 min. Any patient with persistent erection after macologically induced prolonged erection. 4 h received the standard intracorporeal irrigation of dilute adrenaline solution. Patients’ blood pressure and pulse rate were monitored during this period.

Correspondence: S Priyadarshi Asst. Professor, Depart- ment of Urology, SMS Medical College & Hospital, C-80, Results Gole market, Jawahar Nagar, Jaipur 302004, India. E-mail: [email protected] Received 15 December 2002; revised 3 September 2003; Of the 500 impotent patients receiving the intracor- accepted 5 November 2003 poreal injections, 68 (13. 6%) developed prolonged Terbutaline in prolonged erection S Priyadarshi 425 erection. In all, 34 patients were put into each stimulation to the sympathetic nerve trunk abol- treatment arm by computerized random assignment. ished penile erection induced by intracavernosal The age of the patients varied from 24 y to 65 y. papaverine injection in canine models.6 It is Mean age in the control group was 38 y and 40 y possible that terbutaline acts somewhere to stimu- in the terbutaline group. Dosage of the bimix late the sympathetic nervous system causing flac- solution ranged from 0.1 to 0.5 ml. each milliliter cidity of penis. Being a b2 agonist it causes smooth containing 29.25 mg of papaverine and 0.625 mg of muscle relaxation particularly of bronchioles and chlorpromazine. Patients with a prior history of uterus. It is widely prescribed for the treatment of prolonged erection or neurogenic impotence were bronchial asthma. Parenteral terbutaline has also started with the minimum dose of 0.1 ml and the rest been successfully used in intraoperative penile were started with 0.2 ml. Mean dose of bimix erection.7,8 It probably acts by relaxing the smooth solution in the control group was 0.27 ml and muscle of cavernous tissues, arteries, veins, polsters 0.29 ml in the terbutaline group. Detumescence in the blood vessels and Buck’s fascia. The caver- was achieved in 14 patients receiving oral terbuta- nous smooth muscles are not only mechanically line whereas only 5 patients had detumescence stretched due to rapid filling of blood but they when a placebo was used. contract (like a stretched spring) against the blood Fisher’s exact test confirmed that terbutaline was providing rigidity. Terbutaline probably acts by significantly more effective than placebo (Po0.05). relaxation of the stretched corporeal smooth mus- Three patients required 15 mg, five, 10 mg and the cles, relaxation of polsters in the penile veins, rest six 5 mg for the desired response (complete widening of the diameter of the corporeal draining detumescence). veins and removal of impediment of venous blood The aetiology of erectile dysfunction for patients flow created by contracting polsters resulting in with prolonged erection was psychogenic in 31 penile flaccidity.9 patients, neurogenic in 13 and vasculogenic in 34. Terbutaline is given cautiously in patients with Terbutaline was successful in reversing prolonged coronary artery disease, increased intravascular erection in four of 16 patients with psychogenic fluid volume, (Pulmonary) oedema and hypokalae- 10 impotence, four of six neurogenic and six of mia. Detumescence due to b2 agonist may also be 12 vasculogenic impotence. Placebo group due to increased permeability of erectile cavernous showed reversal of prolonged erection in three of tissue permitting easy flow of fluid from sinusoids 12 patients with vasculogenic impotence and one into the venous system. each of 15 and seven of psychogenic and neuro- The study clearly suggests the efficacy of terbuta- genic, respectively. line in a controlled fashion. Further study is needed Terbutaline was most effective in neurogenic to elucidate the exact mechanism of action of the impotence (66.5%) followed by vasculogenic drug. Oral medical therapy for the treatment of (50%) and psychogenic (25%). Terbutaline was pharmacologically induced prolonged erection is unsuccessful in 20 of 34 patients (58%). All these important since medication may be self-adminis- were managed successfully with the standard treat- tered at home at the appropriate time. The cost of ment of intracorporeal irrigation with dilute adrena- managing the complication can be reduced. How- line solution. None of the patients required any ever it was successful in only 42% of the patients surgical intervention. Monitoring of vital signs treated and the remainder required standard intra- showed no significant changes of blood pressure corporeal therapy to achieve full detumescence. in either group. Tacycardia was noticed in 10 of Based on the results of this placebo-controlled 34 (30%) patients in the terbutaline group but study, we recommend initial treatment of pharma- was transient and did not require any medical cologically induced prolonged erections with oral management. terbutaline in patients who do not have significant coronary artery disease or hypersensitivity to this drug. Discussion

The mechanism of action of terbutaline sulphate, a References b2 agonist with minor b1 effects in causing penile detumescence has not been clearly elucidated. It has some alpha agonistic activity too. Haemodynami- 1 Lue TF, Tanagho EA. Physiology of erection and pharmacolo- cally blood flow into the erect corpus is minimal gic management of impotence. J Urol 1987; 137: 829–836. when the intracavernous pressure is 90–100 mmHg. 2 Lomas GM, Jarow JP. Risk factors for papaverine induced Any oral medication would have little direct effect priapism. J Urol 1992; 147: 1280–1281. 3 Brindley GS. New treatments for priapism (Letter). Lancet on the cavernous smooth muscle because of very 1984; 2: 220–221. low level of the drug in the cavernosal blood. 4 Zorgniotti AW, Lizza EF. Diagnosis and Management of Experimentally it has been shown that electrical Impotence. BC Decker: Philadelphia, 1991, 100pp.

International Journal of Impotence Research Terbutaline in prolonged erection S Priyadarshi 426 5 Lowe FC, Jarow JP. Placebo-controlled study of oral 8 Shantha TR, Finnerty DP, Rodriguez AP. Treatment of terbutaline and pseudoephedrine in management of prosta- persistent penile erection and priapism using terbutaline. glandin E1 induced prolonged erections. Urology 1993; 42: J Urol 1989; 146: 1427–1429. 51–53. 9 Goldstein AM et al. New observations on microarchietecture 6 Diederichs W, Stief CG, Lue TF, Tanagho EA. Sympathetic of corpora cavernosa in man and possible relationship to inhibition of papaverine induced erection. J Urol 1991; 146: mechanism of erection. Urology 1982; 20: 259. 195–198. 10 Wheeler AS, Patel KF, Spain J. Pulmunory oedema during 7 Shantha TR. management of penile erection by using terbuta- beta-2 tocolytic therapy. Letter to the editor. Anesth Analg line. Anesthesiology 1989; 70: 707–709. 1981; 60: 695.

International Journal of Impotence Research