A man with diagnosis of HIV is admitted to the clinic for infectious diseases due to a recurrence o

Fråga: A man with diagnosis of HIV is admitted to the clinic for infectious diseases due to a recurrence of pneumonia. Treatment with amoxicillin 750 mg twice a day was started 960404 and eight days later he developed urticaria. Treatment with amoxicillin was stopped and the urticaria subsided after a couple of days. The second day of the urticarial reaction the patient had a hypostatic pain and his legs were marbled. These symptoms disappeared in two days. The patient was also treated with methadone, aciclovir, acetylcysteine and cetirizine. Erythromycin was used to continue the treatment of pneumonia. What is the possible relationship between these symptoms and amoxicillin?

Sammanfattning: Urticaria is a well known adverse reaction to treatment with amoxicillin. In the present case marbled legs with hypostatic pain were also seen when the patient was in an upright position. As the patient has a diagnosis of HIV one could speculate about exceptional hypersensitive reactions. However, no reports concerning hypostatic pain or marbled legs connected to treatment with amoxicillin were found.

Svar: Amoxicillin is a semisynthetic penicillin related to ampicillin. It is also available in combination with clavulanic acid (Augmentin). There is a cross allergenicity between ampicillin and amoxicillin, so that amoxicillin causes similar allergenic phenomena. Amoxicillin may cause a maculo papular rash in some patients, probably as often as ampicillin. The pathogenesis of this rash is unknown, but it has been attributed to lymphocyte function, which might explain its significant higher frequency in glandular fever (1).

According to (2) hypersensitive reactions to penicillin occur in one per cent to about ten per cent of patients treated. These reactions include mainly anaphylactic chock, urticaria/angioedema and bronchial obstruction. A thorough literature search in Medline and common pharmacological handbooks did not reveal any specific information concerning urticaria and/or hypostatic pain in relation to amoxicillin.

The files of the Swedish Adverse Drug Reactions Advisory Committee (SADRAC) contain 506 cases of cutaneous reactions reported since 1975. Among these are 97 cases of urticaria. No cases of hypostatic pain and/or marbled legs were found in the register.

The WHO database contains no reports of hypostatic pain during treatment with amoxicillin. 1 Dollery, Therapeutic drugs. 1991; I: 2 Meyler´s, Side effects of drugs. Ed by MNG Dukes. Elsevier, Amsterdam.