Experiments investigating the possible interaction of tetrahydrocannabinol (THC) and cannabidiol (CBD), two major components of marihuana, were conducted under controlled laboratory conditions in a double-blind manner. In one study, 15 male volunteers were given placebo or 25 mug/kg of THC together with either placebo or 150 mug/kg of CBD by inhalation of the smoke of a single cigarette. All four treatments were assigned to each subject according to a series of Latin-square designs. CBD significantly attenuated the subjective euphoria of THC. Psychomotor impairment due to THC was not significantly altered by the simultaneous administration of CBD, but a trend indicating a decrease in THC-like effects was observed after the combination. When administered alone CBD was inactive for all the parameters measured. In a second study, 8 male subjects were given CBD (0 or 150 mug/kg) by smoke inhalation 30 min before THC (0 or 25 mug/kg) in a second cigarette. In contrast to the simultaneous administration of both drugs, CBD pretreatment did not alter the effects of THC on the parameters observed.

Twelve male volunteers smoked a marihuana cigarette prepared to deliver 0 or 25 mug/kg tetrahydrocannabinol (THC) 50 min after ingesting a capsule containing either placebo or 150 mg/70 kg sodium secobarbital. Drugs were administered in a double-blind manner, and all treatments were assigned to each subject in a randomized complete block design. Objective and subjective tests designed to measure mental and motor performance indicated that marihuana impaired stability, hand-eye coordination, and mental performance. Secobarbital affected motor performance, manual coordination, and mental performance. In combination, marihuana and secobarbital had an additive effect on subjective responses and impairment in certain psychomotor performance tests.

Introduction:Gentamicin is an aminoglycoside antibiotic with broad-spectrum bactericidal activity and is widely used in pediatric units to treat infection with susceptible organisms. This study aimed to describe the dosage regimen for gentamicin and approach to its therapeutic drug monitoring (TDM) among the pediatric units within the state of New South Wales (NSW).Methods:A questionnaire was sent electronically to representatives of 40 pediatric units in NSW, requesting details of each unit’s gentamicin dosing and TDM policy.Results:A total of 35 units responded to the survey. The majority (63%) of the units used a dose of 7.5 mg/kg of gentamicin in patients with normal renal function. More than half of the units (54%) did not have a local gentamicin dosing protocol and relied on other sources for dosing regimens. Dosing responses varied from a dose of 6 mg/kg once daily for patients more than 10 years of age to 7 mg/kg once daily on day 1, followed by 5 mg/kg once daily for patients over 10 years of age. For TDM of gentamicin, 63% of units indicated use of trough levels and 23% units used the Hartford Nomogram.Conclusions:A significant variation exists in clinical practice among pediatric units in NSW on gentamicin dosing and TDM guidelines. There is an urgent need for collaboration among nursing, medical, and pharmacy experts to achieve consensus to develop and adopt statewide uniform guidelines on gentamicin dosing and TDM.