Abstract
To the Editor
Several psychotropic medications such as lithium, valproate and antidepressants like fluoxetine have the potential to cause alopecia areata or diffuse hair loss over the scalp (Warnock, 1991). Antipsychotics, however, have a lesser propensity to cause such side effects (Gautam, 1999). We report a case of alopecia as an adverse effect of a haloperidol decanoate depot injection.
A 38-year-old male, with nil contributory family, past and personal history, was diagnosed as suffering from paranoid schizophrenia and was started on trifluoperazine 15 mg daily. Owing to a poor response, he was then tried on olanzapine 20 mg, to which he also responded poorly, and consequently he became noncompliant. At the time of being referred to us, he had been drug free for at least 6 months. Considering his poor compliance, the long-acting injectable antipsychotic haloperidol decanoate 50 mg was started. Nine days after the first dose of haloperidol decanoate, he started to experience loss of hair over circumscribed areas of the scalp and subsequent regrowth of white hairs over those patches. A complete physical examination was unremarkable except for the patchy areas of hair loss on the scalp. All hematological and biochemical investigations including tests for syphilis/HIV/rheumatoid factor/antinuclear antibody/anti-thyroglobulin antibody and anti-thyroid peroxidase antibody were unremarkable. A dermatological referral was then taken which opined it to be alopecia areata. The Naranjo Adverse Drug Reaction Assessment yielded a score of 7, indicating a highly probable chance that the hair loss was due to the medication (Naranjo et al., 1981).
Discontinuation of depot haloperidol was considered and offered to the patient, but he refused citing considerable improvement in his symptoms and reporting his hair loss to be less distressing than his hallucinations. Keeping this in mind, haloperidol decanoate was continued and he continues to remain asymptomatic at 6 months’ follow-up.
Psychotropic-induced dermatological adverse effects such as hair loss can lead to noncompliance and cause severe distress because of its cosmetic implications. To the best of our knowledge, haloperidol-induced alopecia areata has been reported previously only once (Kubota et al., 1994), which was due to an oral formulation whereas our report is due to the depot preparation. This is even more important because of the slow reversal of side effects due to the long half-life (3 weeks) of depot haloperidol. Several mechanisms have been proposed as to causation, including chelation of zinc and selenium, which are minerals held to be critical for the development and maintenance of the structural integrity of hair (Potter and Ketter, 1993); the role of the T-cell-mediated inflammatory process (Gilhar et al., 2002); and autoimmune reactions due to haloperidol’s actions on the monoaminergic pathways (Kubota et al., 1994). The rarity of such an adverse effect may also be due to prolactin elevations caused by haloperidol, leading to hirsutism (Gautam, 1999). To conclude, cosmetically important adverse effects such as hair loss need to be factored into management decisions, especially when long-action formulations are used.