Substance abuse in women of childbearing age is a global public health problem. The most common drugs of abuse are cocaine, diamorphine (heroin) and alcohol. Fetal drug exposure can be identified by maternal history (which is not always reliable), maternal and infant urine toxicology screening, and meconium and infant and maternal hair analysis.The opioids most commonly associated with withdrawal in neonates are diamorphine, morphine and methadone. Neonatal withdrawal or abstinence syndrome (NAS) occurs in 50 to 80% of infants exposed to opioidsin utero,usually within the first 24 to 72 hours after birth. Only 5 to 20% of these infants will have severe symptoms and need pharmacotherapy.Signs of withdrawal include effects arising from the central nervous, vasomotor, respiratory and gastrointestinal systems. The most serious problems are vomiting and diarrhoea resulting in dehydration, electrolyte imbalance, bodyweight loss, aspiration pneumonia, respiratory alkalosis from tachypnoea, and seizures. There are a number of scales that can be used for assessing the need for pharmacotherapy in NAS. The goal of treatment is for the infant to be comfortable and able to sleep between feeds without being deeply sedated.Pharmacological agents used for treating opioid NAS include both opioid and non-opioid drugs. The most commonly used drugs are paregoric, diluted tincture of opium, and phenobarbital (phenobarbitone). Paregoric, a solution of opium alkaloids - morphine and codeine (analgesics), narcotine and papaverine (antispasmodics) - is used in doses of 3 to 6 drops every 4 to 6 hours. Tincture of opium alkaloids, for use in the neonate, must be reconstituted (25-fold dilution) by the hospital pharmacy to a concentration of 0.4% to reduce the content of morphine to that in paregoric (0.4 mg/ml). This avoids the adverse effects associated with the presence of other ingredients in paregoric. Phenobarbital is an analgesic and anticonvulsant. It has a prolonged half-life and is especially useful in reducing the hyperactive behaviour associated with NAS. It is important to closely monitor the efficacy of therapy by assessing patient response through the use of objective measures.The psychosocial aspects of drug abuse are important to keep in mind, as the infant continues to be at high risk for neglect, abuse and foster care placement.