Neonatal withdrawal, neonatal abstinence syndrome (NAS) or neonatal opioid withdrawal syndrome (NOWS) is a drug withdrawal syndrome of infants, caused by the cessation of the administration of drugs which may or may not be licit. Tolerance, dependence, and withdrawal may occur as a result of repeated administration of drugs, or after short-term high-dose use—for example, during mechanical ventilation in intensive care units. There are two types of NAS: prenatal and postnatal. Prenatal NAS is caused by discontinuation of drugs taken by the pregnant parent, while postnatal NAS is caused by discontinuation of drugs directly to the infant.
Signs and symptoms Those diagnosed with NAS may exhibit signs and symptoms that vary depending on the type of drugs used by the parent, how long the drugs were used, the amount of drug used that made it to the child, and symptoms associated with premature birth. Symptoms can appear as soon as 24 to 48 hours and as late as 5 to 10 days after birth. If the neonate (a newborn less than 4 weeks of age) is expected to have NAS, they may need to stay in the hospital to be monitored for a week. A baby born at full-term may commonly exhibit symptoms such as mottling (net-like bluish-red skin due to swollen blood vessels), irritability, trembling, excessive or high-pitched crying, sleeping problems, increased muscle tone, overactive reflexes, seizures, yawning, stuffy nose, sneezing, poor feeding, rapid breathing, slow weight gain, vomiting, diarrhea, sweating, fever or unstable temperature. These symptoms mainly arise from the dysregulation of four physiological and or behavioral systems: state control and attention which influence irritability and avoidance of eye contact; motor and tone control which influence tremors and seizures, sensory processing which influences hypersensitivity or hyposensitivity, and autonomic control which influence patterns of respiration and fever. Each of these can influence the dysregulation of another system. For example, hypersensitivity in the sensory processing system can cause poor feeding due to the inability to relax, which therefore ultimately results in weight loss or poor weight gain. Signs and symptoms are also grouped into three systems by the Finnegan Neonatal Abstinence Scoring System (FNASS):
Central nervous system. Includes deficiencies in sleep after eating and myoclonic (uncontrolled movement) jerk. Metabolic, vasomotor, and respiratory. Includes symptoms like a stuffy nose and tachypnea. Gastrointestinal. Includes excessive sucking and poor feeding. Babies born prematurely (before 37 weeks) often exhibit less symptoms or in less severity than those born at full term (38 to 42 weeks). This is due to being exposed to the drug for a lesser period of time during pregnancy. Premature babies with NAS tend to recover at a much faster rate than a full term baby would. Both neonatal and maternal factors such as gestational age (length of pregnancy starting from the first day of the last menstrual period), maternal substance use, genetics, and gender play a role in the symptoms expressed by the neonate. Every infant is unique in which symptoms are expressed. Males are prone to having more severe symptoms compared to females and those with hypermethylation at the OPRM1 and COMT gene sites experience more severe symptoms as well. Symptoms can also appear and disappear and fluctuate in severity over time within the same infant and withdrawal period. Untreated NAS symptoms can cause developmental issues such as altered cognitive, social, emotional, and behavioral capacities that appear later in life. Long term effects vary by the substance that the neonate gets exposed to but they most commonly have been shown to affect growth, behavior, cognitive function, vision problems, motor problems, language, academic achievement, otitis media (infection or inflammation of the middle ear), and predisposition to self utilization of drugs. Alcohol exposure could lead to poor growth. Tobacco exposure can increase the risk of obesity. Alcohol, nicotine, and opiate exposure have shown to lead to attention deficits. Nicotine and alcohol exposure affect learning and memory. Cocaine exposure affects visual and motor skills, attention, and memory. Cannabis has been shown to have adverse effects on deep problem solving skills and visual memory. Nicotine exposure has led to poor reading abilities. Alcohol and cocaine led to a decreased use of language. Opioid exposure has led to visual impairments such as reduced ability to see fine detail and uncontrolled eye movements. Heroin exposure led to lower weight, height, and head circumference as well as decreased cognitive function that resulted in lower perceptual, quantitative, and memory areas of cognition. Some common drugs that could result in NAS withdrawal or withdrawal-like symptoms in neonates are:
Opioids; agonists such as morphine, codeine, methadone, meperidine, oxycodone, propoxyphene, hydromorphone, hydrocodone, fentanyl, tramadol, and heroin, antagonists such as naloxone, and naltrexone, and mixed agonist-antagonists like pentazocine and buprenorphine; CNS stimulants; amphetamines such as dextroamphetamine, methamphetamine, amphetamine sulfate, amphetamine congeners, benzphetamine, diethylpropion, fenfluramine, phendimetrazine, phentermine, cocaine, methylphenidate, pemoline, phencyclidines, and nicotine; CNS depressants; alcohol, barbiturates, benzodiazepines, other sedative hypnotics, methaqualone, glutethimide, chloral, hydrate, cannabinoids, cannabis, and hashish; Hallucinogens; indolealkylamines, phenylethylamines, phenylisopropylamine, inhalants, solvents and aerosols, nitrites, and nitrous oxide.
Cannabis There are pre- and post-natal exposure risks of neurobehavioral disorders. Exposure during pregnancy can cause low birth weight, reduced head circumference, cognitive deficits, emotional dysregulation, high impulsiveness, and higher risk to develop a substance disorder. The effects can continue into early adulthood.
… excerpt ends here. Continue reading the full article.
