After a BBC investigation in April showed the extent of codeine addiction in Nigeria, the production of codeine-based syrups was banned.

But codeine is not the only opioid scourge spreading across west Africa.

Another painkiller, Tramadol, is fuelling widespread opiate abuse and addiction.

As the BBC’s Stephanie Hegarty found out, it may even be fuelling the Boko Haram insurgency in the north-east.