An addict presents with increased sweating, lacrimation, diarrhea, yawning and rhinorrhea. These symptoms may occur due to withdrawal of?

Heroin is a semi synthetic derivative of opium. Withdrawal symptoms are lacrimation, sweating, yawning,anxiety,restlessness, rhinorrhoea and tremors seen 8-12 hours after last dose. All the other drugs donot have the above set of side effects. Ref: KD Tripathi 8th ed.