Methamphetamine overdose

Not all experts recommend forced diuresis and urinary pH manipulation after methamphetamine overdose because of the risk of renal damage. 

Sribanditmongkol P, Chokjamsai M, Thampitak S. Methamphetamine overdose and fatality 2 case reports. J Med Assoc Thai 2000 83(9) 1120-3. 

Other effects caused by methamphetamine include headaches, decreased appetite, dry mouth, dilated pupils, trembling, chest pains, increased respiration and shortness of breath, hyperthermia (elevated body temperature), insomnia, and nausea and vomiting. In more severe cases (i.e., overdoses) it can produce seizures and convulsions, stroke, heart attacks, and death. The risk of encountering these more serious side effects are greatly increased when methamphetamine is used in combination with other drugs like cocaine, marijuana, alcohol, and heroin. 

This book will focus on forensic pharmacology and drugs of abuse. Drugs of abuse, such as cocaine, heroin, marijuana, PCP, benzodiazepines, and methamphetamine, are often involved in criminal and civil matters concerning personal injury, motor vehicle accidents, drug overdose, and murder, and thus, are discussed to illustrate forensic pharmacology issues and investigations. 

In the case study presented at the beginning of this chapter, the patient intravenously self-administered an overdose of methamphetamine, a weak base. This drug is freely filtered at the glomerulus, but can be rapidly reabsorbed in the renal tubule. Administration of ammonium chloride acidifies the urine, converting a larger fraction of the drug to the protonated, charged form, which is poorly reabsorbed and thus more rapidly eliminated. ... 

For those who take GHB deliberately, the objective is to take the right amount to achieve the desired high. But the drug is unpredictable and users risk deadly overdose, which can occur within 15 minutes of ingestion. An overdose can result in such severe adverse effects as vomiting, difficulty breathing, seizures (especially when GHB is combined with methamphetamine), unconsciousness, coma (especially when combined with alcohol), and death. 

Like other club drugs—including ecstasy (MDMA), ketamine, GHB (gamma-hydroxy butyrate), methamphetamine, and LSD (d-lysergic acid diethylamide)—Rohypnol is easily accessible and relatively inexpensive. Often, users who intentionally take the drugs to get high at rave parties or elsewhere may not even know what they have taken or been given, which can make it difficult for medical professionals to treat them if they overdose or have a reaction. 

Many recreational drugs such as benzodiazepines, amphetamines, and opioids are also metabolized by the liver. Although information is scant about the clinical significance and interactions between these drugs and antiretroviral agents, unintentional overdoses with methamphetamine and gamma hydroxybutyrate have been reported in patients using Pis, particularly ritonavir. Pis and NRTIs may alter metabohsm of methadone and precipitate opioid withdrawal (McCance-Katz et al., 2003). 

In addition to the hazards associated with meth production, it is becoming increasingly clear that heavy meth users risk a number of health problems. Exposure to very high doses poses a risk of seizures, convulsions, and cardiovascular collapse. Overdose can also produce the paranoid symptoms of stimulant psychosis often associated with violent behavior. A recent study of young adults who were heavy meth users found that over one third of the respondents reported committing acts of violence while under the influence of meth (Sommers, Baskin, Baskin-Sommers, 2006). Chronic users face additional problems. Depression is a common feature of methamphetamine withdrawal... 

Methamphetamine may alter insulin requirements. Symptoms of overdose include increasing restlessness, tremor, hyperreflexia, tachypnea, confusion, aggressiveness, hallucinations, and panic fatigue and depression usually follow the excitement stage. Other symptoms may include arrhythmias, shock, alterations in blood pressure, nausea, vomiting, diarrhea, and abdominal cramps death is usually preceded by convulsions and coma. 

PO. Well absorbed, enters CNS, excreted without undergoing metabolism, half-life = 4-6 hrs. Elimination is slowed by alkalination of urine. Often abused. Severe tolerance and dependence. Methamphetamine ( Speed") acts similarly, but is very addictive and often abused. MAO inhibitors hypertensive crisis, CNS overstimulation. Barbiturates supraadditive mood elevation. Tricyclic Antidepressants potentiate CNS stimulation, inhibit metabolism of amphetamine. Overdose treatment Acidify urine. Give chlorpromazine to treat CNS symptoms and alpha-receptor blocker to lower blood pressure. 

---