Molecular basis of drug action. Receptor specificity and signal transduction. Ionotropic receptors: GABAA and GABAC receptors, glycine receptor, Acetylcholine receptor, excitatory aminoacid receptors: NMDA, AMPA and Kainate. Metabotropic receptors: catecholamine and dopamine receptors. Muscarinic receptors, glutamate receptors, GABAB receptor. Voltage-dependent ionic channels: Na+ channels, K+ channels, Ca2+ channels. Growth factor receptors. Insulin receptor. Cytokine receptors. Nuclear receptors. Immunomodulator and biologic drugs. Nitric oxide. Arachidonic acid cascade. Apoptosis and cellular necrosis.