<qa>  What is the main side effect of minocycline?Minocycline is a semi synthetic derivative of tetracycline. It was first marketed as an antibiotic in 1972. Clinical trials of minocycline have mainly been performed in sexually transmissible diseases and in acne. Minocycline is also used to treat several other diseases such as nocardiasis, mycobacteriosis, leprosy, lyme disease, pyoderma gangrenosum, autoimmune bullous dermatitis, carteaud disease, and prurigo. The usual side effects of minocycline are: lightheadedness, dizziness, or vertigo and pigmentation. 