Newsletter Mechanism of Action of All Drugs This is a pretty comprehensive article that explains the mechanism of action of all commonly prescribed medications.   1. Analgesics Paracetamol (Acetaminophen) Mechanism of Action Weak inhibitor of the synthesis of prostaglandins, Paracetamol also decreases prostaglandin concentrations in vivo. Aspirin Mechanism of Action Aspirin causes reduction of inflammation, analgesia, the prevention of clotting, and antipyretic. Much of this is believed to be due to decreased production of prostaglandins and thromboxane A2 by its irreversible inactivation of the cyclooxygenase (COX) enzyme, Cyclooxygenase is required for prostaglandin and thromboxane synthesis. Diclofenac Sodium Mechanism of Action Diclofenac has analgesic, anti-inflammatory, and antipyretic properties. It causes inhibition of cyclooxygenase (COX 1 and COX 2) and acts as a potent inhibitor of prostaglandin synthesis in vitro. Tramadol hydrochloride Mechanism of Action Tramadol acts on the mu-opioid receptor, blocking the neuron from communicating pain to the brain. Pethidine hydrochloride (Meperidine) Mechanism of Action Pethidine exerts its analgesic effects by acting as an agonist at the μ opioid receptor Morphine Mechanism of Action Morphine is an Opioid analgesic, activating opiate receptors that are widely distributed throughout the brain and body. Once an opiate reaches the brain, it quickly activates the opiate receptors that are found in many brain regions & produce pleasure (or reward) and pain relief. The brain itself also produces substances known as endorphins that activate the opiate receptors. Morphine mimics endogenous neurotransmitters (endorphins). Morphine binds to specific morphine-like (endorphin) receptors ( EndR). Download Pharmacology Books & Thousands of Medical Resources Sample of Pharmacology Essentials Flashcards eBook 2. Antiarrhythmics Adenosine Mechanism of Action Adenosine slows conduction time through the AV node, can interrupt the reentry pathways through the AV node, and can restore normal sinus rhythm in patients with arrhythmias. Amiodarone hydrochloride Mechanism of Action It’s primarily a class III antiarrhythmic. Like other antiarrhythmic drugs of this class, amiodarone works primarily by blocking potassium rectifier currents that are responsible for the repolarization of the heart during phase 3 of the cardiac action potential. Digoxin Mechanism of Action Digoxin increases the force of contraction of the heart muscles by inhibiting the activity of an enzyme (ATPase) that controls the movement of calcium, sodium, and potassium into the heart muscle. Inhibiting ATPase increases calcium in heart muscle and therefore increases the force of heart contractions. Digoxin also slows electrical conduction between the atria and the ventricles of the heart and is useful in treating arrhythmias. Bisoprolol fumarate Mechanism of Action Bisoprolol is a synthetic beta1 selective beta-adrenergic receptor blocker with a low affinity for beta2 receptors in bronchial smooth muscle, blood vessels, and fat cells and no intrinsic sympathomimetic activity. Therefore Bisoprolol exerts cardioselective effects include lower heart rate, decreased cardiac output, and inhibition of renin release by kidneys. At higher doses, it will lose beta1 selectivity. Atenolol Mechanism of Action It’s a Cardioselective beta 1 adrenergic antagonist, works by selectively binding to the beta 1 adrenergic receptors found in vascular smooth muscle and the heart, blocking the positive inotropic and chronotropic actions of endogenous catecholamines, thereby inhibiting sympathetic stimulation. This activity results in a reduction in heart rate, blood pressure, and decreases myocardial contractility. Diltiazem hydrochloride Mechanism of Action Diltiazem is a benzothiazepine derivative with antihypertensive, antiarrhythmic properties. It blocks voltage-sensitive calcium channels in the blood vessels, by inhibiting the ion control gating mechanisms, thereby preventing calcium levels from increase   Get Access to Medical Resources Library Some slides from the presentations from our Medical Resources Library 3. Antibiotics Amoxicillin Mechanism of Action Amoxicillin is in the class of beta-lactam antibiotics. Beta lactams act by binding to penicillin-binding proteins that inhibit a process called transpeptidation, leading to activation of autolytic enzymes in the bacterial cell wall. This process leads to lysis of the cell wall, and thus, the destruction of the bacterial cell. This type of activity is referred to as bactericidal killing. Azithromycin Mechanism of Action Azithromycin prevents bacteria from growing by interfering with their protein synthesis. It binds to the 50S subunit of the bacterial ribosome, thus inhibiting the translation of mRNA. Cefuroxime Mechanism of Action It’s a Cephalosporin group antibiotic, exerts bactericidal activity by interfering with bacterial cell wall synthesis and inhibiting cross-linking of the peptidoglycan. The cephalosporins are also thought to play a role in the activation of bacterial cell autolysins which may contribute to bacterial cell lysis. Cephalexin (Cefalexin) Mechanism of Action It’s a Cephalosporin group antibiotic, exerts bactericidal activity by interfering with bacterial cell wall synthesis and inhibiting cross-linking of the peptidoglycan. The cephalosporins are also thought to play a role in the activation of bacterial cell autolysins which may contribute to bacterial cell lysis. Ciprofloxacin Mechanism of Action Ciprofloxacin is a bactericidal antibiotic of the fluoroquinolone drug class. It acts on bacterial topoisomerase II (DNA gyrase) and topoisomerase IV. Ciprofloxacin’s targeting of the alpha subunits of DNA gyrase prevents it from supercoiling the bacterial DNA which prevents DNA replication. Clarithromycin Mechanism of Action Clarithromycin, a macrolide antibiotic, inhibits bacterial protein synthesis by binding to the bacterial 50S ribosomal subunit. Binding inhibits peptidyl transferase activity and interferes with amino acid translocation during the translation and protein assembly process, and prevents bacterial protein synthesis. Clindamycin Mechanism of Action It is a bacterial protein synthesis inhibitor by inhibiting ribosomal translocation in a similar way to macrolides. It does so by binding to the 23S RNA of the 50S subunit of the ribosome. Clindamycin is bacteriostatic. Co-amoxiclav Mechanism of Action Co-amoxiclav is a combination of Amoxicillin and Clavulanic acid. Clavulanic acid blocks the chemical defense, known as beta-lactamase, that some bacteria produce against penicillin group antibiotics such as amoxicillin. Co-amoxiclav is active against bacterial infections that have become resistant to amoxicillin. Co-trimoxazole Mechanism of Action Co-trimoxazole, generally bactericidal, a combination of trimethoprim and sulfamethoxazole. It acts by sequential blockade of folic acid enzymes in the synthesis pathway. The sulfamethoxazole component inhibits the formation of dihydrofolic acid from para-aminobenzoic (PABA), whereas trimethoprim inhibits dihydrofolate reductase. Both drugs block folic acid synthesis, preventing bacterial cell synthesis of essential nucleic acids. Doxycycline Mechanism of Action Doxycycline is a tetracycline