Part of the acquired hyperpigmentations of the skin are interpreted as adverse effect of drugs.However, systematic studies are rare in the literature.

The purpose of a study published in GiornaleItaliano di Dermatologia e Venereologia attempted to provide a contribution to the body of evidence for a causal relation.

This systematic review reported on an association of hyperpigmentation and drugs from 1970 until April 2016, found in Medline and EMBASE, which were rated according to the SIGN grading system for clinical studies.

Overall, 352 evaluated publications were found, which mainly consisted of reports of single cases—only a small number of larger case series were available. However, case-control-studies and randomized controlled studies have rarely been found. It was noted that the level of evidence for a causal relation to hyperpigmentation is low for the major part of drugs as quoted in order to the Anatomical Therapeutic Chemical Classification System with Defined Daily Doses. A causal relation is likely only for prostaglandins, minocyclin, phenothiazine, nicotine and anti-malaria drugs.

In inference, it was stated that there is paucity of evidence for an induction of hyperpigmentation by drugs. Yet, a causal relationship is likely only in a small number of drugs.

Source: GiornaleItaliano di Dermatologia e Venereologia. 2016 Dec;151(6):694-699.