Psychopharmacology

Psychopharmacotogy 61, 261- 262 (1979)

~' by Springer-Verlag 1979

Benztropine Prophylaxis of Dystonic Reactions T h e o d o r e A. Stern, 1 a n d W i l l i a m H. A n d e r s o n 2 Clinical Fellow in Psychiatry, Harvard Medical School and Senior Resident in Psychiatry, Massachusetts General Hospital and 2 Assistant Professor of Psychiatry, Harvard Medical School and Director of Postgraduate Education, Department of Psychiatry, Massachusetts General Hospital, I Fruit Street, Boston, Massachusetts 02H4, U.S.A.

The effectiveness o f a n t i p a r k i n s o n medic a t i o n for the p r e v e n t i o n o f d r u g i n d u c e d d y s t o n i a s has r e m a i n e d a question. F o r t y p a t i e n t s with acute psychosis w h o received high p o t e n c y oral a n t i p s y c h o t i c drugs were interviewed to d e t e r m i n e the incidence o f acute dystonia. A n eleven-fold increase in d y s t o n i a was f o u n d in p a t i e n t s w h o received no p r o p h y l a c t i c medication. Such p r o p h y l a x i s a p p e a r s effective in preventing acute dystonia. Abstract.

Key words: B e n z t r o p i n e - P r o p h y l a x i s - D y s t o n i a Antipsychotics - Extrapyramidal

Large surveys (Ayd, 1961; Swett, 1975) have s h o w n that 2 % to 10 % o f p a t i e n t s develop d y s t o n i a s while receiving a n t i p s y c h o t i c drugs. Swett et al. (1977) f o u n d t h a t there was no evidence to suggest t h a t b e n z t r o p i n e p r o p h y l a x i s p r e v e n t e d e x t r a p y r a m i d a l s y m p t o m s in patients receiving c h l o r p r o m a z i n e . This r e p o r t describes the incidence o f d y s t o n i c reactions a m o n g forty p s y c h i a t r i c o u t p a t i e n t s w h o received high p o t e n c y oral phenothiazines, a b u t y r o p h e n o n e or a t h i o x a n t h e n e with or w i t h o u t p r o p h y l a c t i c use o f an a n t i p a r k i n s o n agent.

M a t e r i a l and M e t h o d s Introduction

It has been a frequent clinical practice to prescribe anticholinergic drugs t o g e t h e r with neuroleptics in an effort to p r e v e n t the emergence o f e x t r a p y r a m i d a l side effects in the t r e a t m e n t o f psychosis. This practice has led to c o n t r o v e r s y in the literature with some a u t h o r s questioning the effectiveness o f this m e a s u r e as well as its safety ( D i M a s c i o a n d Sovner, 1976; Baldessarini a n d Lipinski, 1976). D y s t o n i a consists o f the i n v o l u n t a r y tonic contractions o f skeletal muscles. F r e q u e n t l y frightening to the patient, it m a y result in c h i p p e d teeth or dislocation o f the t e m p e r o - m a n d i b u l a r joint. C o m m o n l y involving b r a n c h i o m e r i c m u s c u l a t u r e , it m a y be ascribed to seizure disorder, tetany, t e t a n u s or to 'hysteria'. M a n y clinicans use b e n z t r o p i n e or similar agents in this early t r e a t m e n t p h a s e in the hope o f a v o i d i n g this distressing side effect. D u r i n g this critical time that the psychosis is being resolved, the t h e r a p e u t i c alliance between p a t i e n t a n d p h y s i c i a n is n o t yet strong. Experiencing an u n c o m f o r t a b l e a n d frightening side effect m a y then drive a p e r s o n f r o m receiving treatment.

From the patient population of the Acute Psychiatric Service at the Massachusetts General Hospital a group of eighty-two consecutive patients receiving oral high potency antipsychotic medication in doses equivalent to chlorpromazine 200 mg or more per day was identified. Patients who had received antipsychotic medication in the two months preceding the index visit were excluded from the study. Patients receiving parenteral antipsychotic medications were also excluded. The records of the selected patients were reviewed with special attention to medication administered between January and December, 1977. This information was also verified by contact with the examining physician. We defined benztropine prophylaxis as the concurrent administration of benztropine and antipsychotic medication from the beginning of treatment. Follow-up phone calls were made to all patients included in the study. Contact was made between 2 weeks and 6 months after initiation of treatment with a mean of 12.7 weeks. We were able to contact and obtain complete information on 40 of the 82 patients in our sample. Those who were contacted were similar in age and sex to the 42 who could not be interviewd. The dosage of medication received did not differ between these two groups. Patients were asked in a standardized interview format to recall the treatment medications, their duration of use, the therapeutic effects and side effects, and any remedial action taken for side effects. They were specifically asked about stiffness of the muscle in the face, neck or tongue. A patient was judged to have experienced dystonia if there was complaint of tightened cervical muscles and if anticholinergic treatment was begun.

0033-3158/79/0061/0261/$ 01.00

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Psychopharmacology61 (1979)

Table 1

Drug

Dose Range

no. Dystonic

Haloperidol

5 - 40 mg/d 5 - 15 mg/d 16- 40 mg/d

10/21 6/16 4/5

10- 30 mg/d

1/16

Trifloperazine Fluphenazine

10 mg/d

1/2

Thiothixine

20 mg/d

1/1

Results

Of the total of 82 patients, adequate follow-up information was available on 40 (48 %). Of the remaining 42 patients, 39 could not be reached and 3 gave incomplete data. The mean age of all patients was 29.4 years (men, 27.5 years; women, 31.4 years) with an age range of 17 - 68 years. Half of the sample was male. All patients were diagnosed as psychotic. Diagnosis included acute psychosis, paranoid schizophrenia, and affective psychosis. Of the 40 responders, 13 patients had dystonic reactions (33 %) - one patient with benztropine prophylaxis, 12 patients without prophylaxis. The only case of dystonia with concurrent benztropine prophylaxis occurred in an 18-year-old male receiving 40 mg/day of haloperidol. In each case the dose of benztropine prophylaxis was 2mg/day. The relative incidence of dystonia in patients without prophylaxis was 11.1. Data analysis by Fisher's exact method showed significance at P = 0.012. The 14 patients in the group with prophylaxis had a mean age of 26.2. The patients receiving no prophylaxis had a mean age of 31.2. The group with prophylaxis received an average daily dose of 407 mg chlorpromazine equivalent. The group without prophylaxis received 398 rag. Patients with acute dystonia received

an average of 585 mg chlorpromazine equivalent and those without dystonia received an average of 344 rag.

Discussion

It is certainly possible that benztropine, while it is effective as a preventative for dystonia, may not be effective in preventing other drug-induced disorders. It is also possible that the higher incidence of dystonic reactions observed here is a result of the exclusive use of high potency antipsychotic medications. It appears that the initial use of benztropine prophylaxis markedly reduces the incidence of dystonic reactions in patients using oral high potency antipsychotics. This finding is not consistent with earlier work that suggested little clear benefit from prophylactic use of antiparkinson medication. One possible explanation for this difference is that former studies considered the aggregate of all extrapyramidal reactions, whereas this study considers only dystonia.

References

Ayd, F. J.: A Survey of drug-induced extrapyramidal reactions. JAMA 175, 1054-1060 (1961) Baldessarini, R. J., Lipinski, J. F. : Toxicity and side effects of antipsychotic, antimanic and antidepressant medications. Psychiatric Annals 6, 484-493 (1976) DiMascio, A., Sovner, R. D. : Neuroleptic-inducedextrapyramidal side effects. Drug Therapy 6, 99-103 (1976) Swett, C. : Drug-induceddystonia. Am. J. Psychiatry132, 532-534 (1975) Swett, C., Cote, J. O., Shapiro, S., Slone, D. : Extrapyramidal side effects in chlorpromazinerecipients. Arch. Gen. Psychiatry34, 942-943 (1977)

Received September8, 1978; Final Version December 11, 1978

Benztropine prophylaxis of dystonic reactions.

Psychopharmacology Psychopharmacotogy 61, 261- 262 (1979) ~' by Springer-Verlag 1979 Benztropine Prophylaxis of Dystonic Reactions T h e o d o r e...
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