In Europe, a hair loss drug is being investigated because it is linked to suicidal thoughts

The European Medicines Agency's review of finasteride, which is available as both a pill and a solution that can be applied directly to the skin, stems from concerns about a possible link between the drug and suicidal thoughts. Finasteride can also be used to treat men with an enlarged prostate. Another drug called dutasteride, also used to treat an enlarged prostate, is also being reviewed by the EMA.

Medications containing finasteride and dutasteride carry a “known risk of psychiatric side effects, including depression,” when taken orally, the regulator said in a statement. Suicidal thoughts have already been included as a possible side effect in the product information of two medications containing finasteride – Propecia and Proscar.

Now the EMA says it will examine all the evidence to decide whether the approvals for these drugs in the European Union should be maintained, changed, suspended or withdrawn.

Meanwhile, Britain's medicines regulator urged men taking finasteride to be aware of possible psychiatric and sexual side effects. Britain's Medicines and Healthcare products Regulatory Agency announced in April that a new patient warning card would be introduced in finasteride packs this year. In the UK, only oral finasteride is approved, not the topical product.

Generic finasteride is available from several manufacturers, under the brand names Proscar and Propecia, both manufactured by Merck and known as MSD outside North America.