Toxicology · Short notes

Narcotics and Psychotropic Substances: Short Notes & Cheat Sheet

Drugs of abuse seen in Pakistan, their sources, presumptive colour tests, metabolites and the laws and conventions that control them.

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Short notes

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Narcotics control in Pakistan

Enforcement, licit supply and analysis are handled by different bodies under the same law and conventions.

Common drugs of abuse

Heroin (diacetylmorphine) is made by acetylating morphine with acetic anhydride; street heroin is often cut with caffeine and paracetamol.
Cannabis: charas is resin, bhang is leaves and ganja is flowering tops; THC is the main psychoactive constituent.
Methamphetamine ('ice') is made from ephedrine, pseudoephedrine or P2P; its misuse has risen in Pakistan.
Cocaine comes from Erythroxylum coca; crack is the smokable freebase.
Prescription drugs misused include tramadol, codeine syrups, benzodiazepines and pregabalin.
New psychoactive substances include synthetic cannabinoids and cathinones, often missed by routine screens.

Law and enforcement

The Control of Narcotic Substances Act 1997 controls narcotic drugs, psychotropic substances and precursor chemicals.
The Anti-Narcotics Force (ANF) is the federal enforcement agency, working with police, customs and excise.
DRAP handles legitimate medical supply of controlled medicines, including quotas and import permissions.
UN conventions: 1961 Single Convention (narcotics), 1971 (psychotropics), 1988 (trafficking and precursors).
The INCB in Vienna monitors the conventions and licit supply estimates.

Analysing seizures

Presumptive colour tests guide which confirmatory method to use.
GC-MS confirms identity; quantitation gives purity and helps intelligence profiling.
Impurities such as noscapine and papaverine in heroin indicate opium-derived manufacture.
Chiral analysis of methamphetamine can indicate the precursor route.
Fentanyl analogues are active in microgram amounts, so analysts need protective handling.

Cheat sheet

High-yield facts in one place. Cover the right-hand column and test yourself.

Colour test → target

Reagent	Positive for
Marquis	Opiates (purple); amphetamines (orange-brown)
Duquenois–Levine	Cannabis (purple in chloroform layer)
Cobalt thiocyanate (Scott)	Cocaine (blue)
Simon's	Secondary amines, e.g. methamphetamine (blue)
Ehrlich (p-DMAB)	LSD and indoles (purple)
Dille–Koppanyi	Barbiturates (violet)
Mecke	Opiates (green to blue)

Street name → drug

Street name	Drug
Charas	Cannabis resin
Bhang	Cannabis leaves
Ice / crystal	Methamphetamine
Smack / brown sugar	Heroin
Crack	Freebase cocaine
Ecstasy	MDMA
Spice	Synthetic cannabinoids

Precursor → product

Precursor	Illicit product
Acetic anhydride	Heroin (from morphine)
Ephedrine / pseudoephedrine	Methamphetamine
Phenyl-2-propanone (P2P)	Methamphetamine or amphetamine
Potassium permanganate	Cocaine refining

Memory aids

Marquis turns Morphine Mauve: Marquis reagent gives purple with opiates; amphetamines go orange-brown.
Scott Spots Snow: Cobalt thiocyanate (Scott) gives blue with cocaine ('snow').
Simon's Secondary: Simon's test detects secondary amines, separating methamphetamine from amphetamine.

Exam traps

Heroin is diacetylmorphine; codeine is methylmorphine.
Charas is resin, not leaves.
Acetic anhydride is a controlled precursor even though it is an industrial chemical.
Synthetic cannabinoids often give negative standard cannabis immunoassays.

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