In FASS it is stated that Norvasc (amlodipine) can cause visual disturbance. What type of/nvisual

Fråga: "In FASS it is stated that Norvasc (amlodipine) can cause visual disturbance. What type of visual disturbances have been described? The question concerns a 62-year-old man who complains of recurrent "migraine aura like" episodes of oscillating scotoma without subsequent migraine. The patient is currently treated with Norvasc (amlodipine) 5 mg x1 and has the impression that the reaction is due to the drug. He has been taking the drug for several years. Also, he is also being treated with Visken (pindolol) 5 mg x1."

Sammanfattning: According to a personal communication to the manufacturer, visual disturbance may occur in patients treated with amlodipine. Our search through the literature revealed however no cases with the exception of two spontaneous case reports in SWEDIS. Both cases had positive dechallenge. In one case, the reaction reappeared upon rechallenge. To ascertain any causal relationship between amlodipine and the patient´s reaction, dechallenge/rechallenge test may be tried.

Svar: An extensive search through Medline, Drugline as well as major text books did not reveal any information on amlodipine and visual disturbances.

However, in SWEDIS, two reports were found on ophthalmological side effects attributed to amlodipine therapy. The first case concerned a 71-year-old man with hereditary atrophic cornea. The patient is reported to have experienced visual impairment already during the first day of amlodipine therapy. Upon discontinuation of the drug, the reaction disappeared (dechallenge positive), and on reinstitution, the reaction reappeared (positive rechallenge). The patient was concomitantly treated with metoprolol in a depot form. The second case concerned a 70-year-old woman who developed diplopia two weeks after starting treatment with amlodipine. Upon discontinuation of the drug, the reaction disappeared. Concomitant drugs included digoxin, paracetamol + dextropropoxyphene, chlorzoxazon and acetyl salicylic acid (1).

According to a new information received from the manufacturer (2, enclosed), it appears that visual disturbances occur in some patients treated with amlodipine. During multiple dose studies of the original clinical development program of amlodipine, about 1.0 per cent of the patients experienced visual disturbances. Review of Pfizer´s early alert safety database identified also one relevant clinical study case and 77 non-clinical study cases of visual disturbances. The most commonly reported reactions were abnormal vision, diplopia, abnormal accommodation and conjunctivitis. Based on this documentation, visual disturbances is listed as a less common side effect of amlodipine in FASS.

Visual disturbance is not listed as a side-effect of pindolol in FASS. In SWEDIS, we found one case of unspecified eye disturbance.