title: Effect of repeated oral therapeutic doses of methylphenidate on food intake and growth rate in rats.
abstract: Central nervous system stimulants are known to produce anorexia. Previous data suggest that methylphenidate can have variable effects on caloric intake and growth rate. A dose-response study was performed to monitor caloric intake, liquid intake and growth rate in rats following repeated administration of human oral therapeutic doses 2 mg/kg/day, 5mg/kg/day and 8mg/kg/day of methylphenidate. We found that food intake and water intake, increased in all weeks and at all doses used in the study. Growth rate increased more at higher dose (8mg/kg/day) and at low dose (2mg/kg/day) of methylphenidate in 1(st) and 2(nd) week whereas more decreased by the above doses in 3(rd) week, suggesting that food stimulation leads to initial increase in growth rate but long term administration of methylphenidate attenuate growth rate that is not due to modulation of appetite but may be due to anxiety and increased activity produce by stimulants. A possible role of DA, 5HT receptors in modulation of appetite and anxiety is discussed.
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, University of Karachi, Karachi, Pakistan.
authors.forename: Nausheen
authors.initials: N
authors.lastname: Alam
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, University of Karachi, Karachi, Pakistan.
authors.forename: Rahila
authors.initials: R
authors.lastname: Najam
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001007:Anxiety / Q000139:chemically induced / Q000523:psychology; D001069:Appetite Regulation / Q000187:drug effects*; D001522:Behavior, Animal / Q000187:drug effects*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage* / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004326:Drinking / Q000187:drug effects; D004334:Drug Administration Schedule; D004435:Eating / Q000187:drug effects*; D002149:Energy Intake / Q000187:drug effects; D008774:Methylphenidate / Q000008:administration & dosage* / Q000633:toxicity; D017208:Rats, Wistar; D013997:Time Factors; D015430:Weight Gain / Q000187:drug effects*
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate