Assessment of abuse liability of pheniramine among opioid-dependent human subjects

Background: Pheniramine is being used harmfully in combination with opiates and benzodiazepines through injecting route. However, the abuse liability of pheniramine has not been studied in humans. Aim: The present study is an attempt to analyze the abuse liability of pheniramine in human subjects. Materials and methodology: The study used a double-blind randomly allotted crossover design. The doses of the drugs used were placebo (normal saline) 2 mL, pheniramine maleate 45.5 mg and lorazepam 2 mg. The assessments were made at baseline and then at 15, 120 and 240 min. The subjects were assessed for the sociodemographic profile, drug-use history, physiological parameters (pulse rate, BP, respiratory rate), and Modified Single-Dose Questionnaire (MSDQ)/Morphine-Benzedrine Group Scale (MBG)/Pentobarbital-Chlorpromazine-Alcohol Group Scale (PCAG)/Visual Analog Scale (VAS)/Profile of Mood States (POMS) scale. Analysis: Analysis was carried out using SPSS version 10.0. In-between drug comparisons were done using one-way analysis of variance (ANOVA) (multiple comparisons). Results: MSDQ and PCAG showed comparable results between the two compounds. VAS and POMS scale had significant increase on the scale for both lorazepam and pheniramine. Conclusions: The findings suggest the possible abuse liability of pheniramine. These findings with the clinical observation of pheniramine abuse used in combination with injection buprenorphine and diazepam warrant the need of caution while prescribing the compound to individuals.