Methaqualone
 NAME OF DRUG:Methaqualone (Quaalude, Sopor) |
| PHYSICAL CHARACTERISTICS: The compound acts like a base but is also soluble in dilute alkaline solutions. |
| DOSAGE/OCCURRENCE/USAGE: Methaqualone is a quinazoline derivative clinically effective as a sedative and hypnotic. In 1965, it was introduced as a barbituate substitute with similar clinical effects. Methaqualone is taken orally and absorbed rapidly in the gastrointestinal tract. For oral use, it is supplied in amounts of 75-300 mg as the free base and 200-400 mg as the hydrochloride. It has become a drug of abuse, being self-administered in oral doses of up to 3 g daily. Chronic usage can result in tolerance and physical dependence. |
| BLOOD CONCENTRATIONS VS. DOSAGE: Estimates of the plasma half-life of methaqualone have ranged from 2.6 - 41.5 hours. The distributive phase, not the terminal elimination phase, is represented in the low figure. The terminal elimination phase, however, has a half-life which averages 33 – 38 hours. During chronic administration of methaqualone, plasma concentrations show initial accumulation but return to levels usually seen with single doses. When 7 subjects were each given 250 mg oral dose of methaqualone base, a mean peak plasma level of 2.2 mg/L (range 1.0 – 4.0) at 2 hours was observed. The levels declined to 1.1 mg/L at 5 hours. |
| URINE EXCRETION RATE: After a 250 mg oral dose, methaqualone urine concentrations usually do not exceed 0.2 mg/L, whereas total (free plus conjugated) 6-hydroxy-methaqualone concentrations range up to 4 mg/mL. Within 24 hours after a similar dose, total urine concentrations of the 3’- and 4’-hydroxy and 2’- and 2-hydroxymethyl metabolites range from 0.8 – 32 mg/L. Metabolite excretion patterns vary due to drug tolerance, individual metabolism, and urine volume. |
| METABOLITES: 0.2% as methaqualone, 6.6% as methaqualone-N-oxide, 10.3% conjugated 4’-hydroxymethylmethaqualone, 4.7% conjugated 2’-hydroxymethylmethaqualone, 3.5% conjugated 3’-hydroxymethaqualone, 2.8% conjugated 2-hydroxymethylmethaqualone, and 2.8% conjugated 6-hydroxymethaqualone. 4’-hydroxy-methaqualone is the most predominant metabolite |
| TOXICITY: Symptoms of overdose range from gastrointestinal distress, drowsiness, ataxia, tingling sensations, slurred speech and muscular hyperactivity, to internal bleeding, convulsion and coma. |
| REFERENCES: Baselt, R C. Disposition of Toxic Drugs and Chemicals in Man, Second Edition. Davis, Calif.: Biomedical Publications, 1982 |