Drugs that act on ionotropic receptors Domina Petric, MD Drugs that act on ionotropic receptors 01

Nicotine nAChR are very important in many cognitive processes. Nicotine is selective agonist of nicotinic acetylcholine receptors (nAChR). nAChR are very important in many cognitive processes. 03

component are especially important for the rewarding Nicotine Rewarding effect of nicotine is associated with ventral tegmental area (VTA) where there are nAChR on dopaminergic neurons. nAChR that contain α4β2 component are especially important for the rewarding effect of nicotine. Abstinence syndrome irritability insomnia Nicotine is very addictive. DEFAULT STYLES 04

Partial agonists of α4β2 nAChR: citizine and varenicline. Treatment Partial agonists of α4β2 nAChR: citizine and varenicline. Bupropion! Cognitive and behavioral therapy. 05

Benzodiazepines and barbiturates Benzodiazepines are safer than barbiturates. Physical addiction on benzodiazepines is very common. Abstinence syndrome: irritability, insomnia, phonofobia, photofobia, depression, muscle cramps and convulsions.

Benzodiazepines and barbiturates Benzodiazepines are positive modulators of GABAA receptors.

Alcohol Alcohol modulates function of several receptors and cell functions: GABAa receptors Kir3/GIRK channels return entry of adenosine glycine receptors NMDA receptors 5-HT3 receptors

Alcohol Physical addiction becomes evident after 6-12 hours of heavy drinking cessation. Abstinence syndrome: tremor (mostly hand tremor), vomit, nausea, excessive sweating, agitation and hearing hallucinations 12 to 24 hours after drinking cessation.

Alcohol Mortality rate of delirium tremens is 5-15%. Generalised convulsions can appear 24 to 48 hours after drinking cessation. After 48 to 72 hours delirium tremens can appear: patient is disoriented, hallucinates and there is autonomic instability. Mortality rate of delirium tremens is 5-15%.

Treatment Treatment of alcohol abstinence syndrome is based on lorazepam and oxazepam. Psycho-social approach is very important.

Ketamin and phencyclidine Ketamin and phencyclidine are non competitive antagonists of NMDA receptors. Psychedelic affect lasts for about an hour. They do not cause addiction. Chronic abuse can cause permanent psychosis similar to schizophrenia.

Inhalant drugs Nitrates, ketones and aromatic hydrocarbons: sniffing, huffing or bagging. Most of inhalant drugs create euphoria: for example, toluene causes increase in VTA excitability. Amyl nitrate (poppers) cause smooth muscle relaxation and improve erection. VTA: ventral tegmental area

Inhalant drugs They have toxic affect on many organs. They cause lesions of white matter in central nervous system. Treatment of overdose is supportive.

Katzung, Masters, Trevor. Clinical pharmacology.