Verapamil is a FDA approved drug used to treat high blood pressure and to control chest pain. Verapamil is an L-type calcium channel blocker that also has antiarrythmic activity. The R-enantiomer is more effective at reducing blood pressure compared to the S-enantiomer. However, the S-enantiomer is 20 times more potent than the R-enantiomer at prolonging the PR interval in treating arrhythmias. Verapamil inhibits voltage-dependent calcium channels. Specifically, its effect on L-type calcium channels in the heart causes a reduction in ionotropy and chronotropy, thuis reducing heart rate and blood pressure. Verapamil's mechanism of effect in cluster headache is thought to be linked to its calcium-channel blocker effect, but which channel subtypes are involved is presently not known.

Mrtoprolol is a beta-adrenergic receptor blocking agent. In vitro and in vivo animal studies have shown that it has a preferential effect on beta-1 adrenoreceptors, chiefly located in cardiac muscle. Clinical pharmacology studies have confirmed the beta-blocking activity of metoprolol in man, as shown by (1) reduction in heart rate and cardiac output at rest and upon exercise, (2) reduction of systolic blood pressure upon exercise, (3) inhibition of isoproterenol-induced tachycardia, and (4) reduction of reflex orthostatic tachycardia. Mrtoprolol is indicated for the treatment of hypertension, angina pectoris and myocardial infarction

Timolol is the non-selective Beta antagonist used as eye drops to treat increased pressure inside the eye such as in ocular hypertension and glaucoma. Timolol is also used for high blood pressure, chest pain due to insufficient blood flow to the heart, to prevent further complications after a heart attack, and to prevent migraines. Timolol is a beta1 and beta2 (non-selective) adrenergic receptor antagonist that does not have significant intrinsic sympathomimetic, direct myocardial depressant, or local anesthetic (membrane-stabilizing) activity. Timolol, when applied topically on the eye, has the action of reducing elevated, as well as normal intraocular pressure, whether or not accompanied by glaucoma. Elevated intraocular pressure is a major risk factor in the pathogenesis of glaucomatous visual field loss and optic nerve damage. The precise mechanism of the ocular hypotensive action of Timolol is not clearly established at this time. Tonography and fluorophotometry studies of the timolol maleate ophthalmic solution in man suggest that its predominant action may be related to the reduced aqueous formation. However, in some studies, a slight increase in outflow facility was also observed. In a study of plasma drug concentration in six subjects, the systemic exposure to timolol was determined following once daily administration of Timolol Maleate Ophthalmic Gel Forming Solution 0.5% in the morning. The mean peak plasma concentration following this morning dose was 0.28 ng/mL. Side effects, when given in the eye, include burning sensation, eye redness, superficial punctate keratopathy, corneal numbness.

Dobutamine is a sympathomimetic drug used in the treatment of heart failure and cardiogenic shock. Dobutamine hydrochloride is a direct-acting inotropic agent whose primary activity results from stimulation of the ß-receptors of the heart while producing comparatively mild chronotropic, hypertensive, arrhythmogenic, and vasodilative effects. It does not cause the release of endogenous norepinephrine, as does dopamine. Dobutamine directly stimulates beta-1 receptors of the heart to increase myocardial contractility and stroke volume, resulting in increased cardiac output. Dobutamine Injection, USP is indicated when parenteral therapy is necessary for inotropic support in the short-term treatment of adults with cardiac decompensation due to depressed contractility resulting either from organic heart disease or from cardiac surgical procedures.

Disopyramide is an antiarrhythmic drug indicated for the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia that are life-threatening. In man, Disopyramide at therapeutic plasma levels shortens the sinus node recovery time, lengthens the effective refractory period of the atrium, and has a minimal effect on the effective refractory period of the AV node. Little effect has been shown on AV-nodal and His-Purkinje conduction times or QRS duration. However, prolongation of conduction in accessory pathways occurs. Disopyramide is a Type 1A antiarrhythmic drug (ie, similar to procainamide and quinidine). It inhibits the fast sodium channels. In animal studies Disopyramide decreases the rate of diastolic depolarization (phase 4) in cells with augmented automaticity, decreases the upstroke velocity (phase 0) and increases the action potential duration of normal cardiac cells, decreases the disparity in refractoriness between infarcted and adjacent normally perfused myocardium, and has no effect on alpha- or beta-adrenergic receptors. It is used for the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia, ventricular pre-excitation and cardiac dysrhythmias. It is a Class Ia antiarrhythmic drug.

Prazosin (trade names Minipress, Vasoflex, Lentopres, and Hypovase) is a selective α-1-adrenergic receptor antagonist used to treat hypertension. Prazosin acts by inhibiting the postsynaptic alpha-1-adrenoceptors on vascular smooth muscle. This inhibits the vasoconstrictor effect of circulating and locally released catecholamines (epinephrine and norepinephrine), resulting in peripheral vasodilation. Prazosin is orally active and has a minimal effect on cardiac function due to its alpha-1 receptor selectivity. However, when prazosin is started, heart rate and contractility go up in order to maintain the pre-treatment blood pressures because the body has reached homeostasis at its abnormally high blood pressure. The blood pressure lowering effect becomes apparent when prazosin is taken for longer periods of time. The heart rate and contractility go back down over time and blood pressure decreases. The antihypertensive characteristics of prazosin make it a second-line choice for the treatment of high blood pressure. Prazosin is also useful in treating urinary hesitancy associated with prostatic hyperplasia, blocking alpha-1 receptors, which control constriction of both the prostate and urethra. Although not a first line choice for either hypertension or prostatic hyperplasia, it is a choice for patients who present with both problems concomitantly. Common (4–10% frequency) side effects of prazosin include dizziness, headache, drowsiness, lack of energy, weakness, palpitations, and nausea. Less frequent (1–4%) side effects include vomiting, diarrhea, constipation, edema, orthostatic hypotension, dyspnea, syncope, vertigo, depression, nervousness, and rash.

Clonidine is a centrally acting α2 adrenergic agonist and imidazoline receptor agonist used to treat high blood pressure, attention deficit hyperactivity disorder, anxiety disorders, tic disorders, withdrawal (from either alcohol, opioids, or smoking), migraine, menopausal flushing, diarrhea, and certain pain conditions. Clonidine treats high blood pressure by stimulating α2 receptors in the brain, which decreases peripheral vascular resistance, lowering blood pressure. It has specificity towards the presynaptic α2 receptors in the vasomotor center in the brainstem. This binding decreases presynaptic calcium levels, thus inhibiting the release of norepinephrine (NE). It has also been proposed that the antihypertensive effect of clonidine is due to agonism on the I1 receptor (imidazoline receptor), which mediates the sympatho-inhibitory actions of imidazolines to lower blood pressure. Clonidines mechanism of action in the treatment of ADHD is to increase noradrenergic tone in the prefrontal cortex (PFC) directly by binding to postsynaptic α2A adrenergic receptors and indirectly by increasing norepinephrine input from the locus coeruleus. Clonidine indicated in the treatment of hypertension. Clonidine hydrochloride tablets may be employed alone or concomitantly with other antihypertensive agents. The US Food and Drug Administration (FDA) has approved clonidine for the treatment of attention deficit hyperactivity disorder (ADHD), under the trade name of Kapvay alone or with stimulants in 2010, for pediatric patients aged 6–17 years.

Ibuprofen is a nonsteroidal anti-inflammatory agent (NSAIA) or nonsteroidal anti-inflammatory drug (NSAID), with analgesic and antipyretic properties. Ibuprofen has pharmacologic actions similar to those of other prototypical NSAIAs, which are thought to act through inhibition of prostaglandin synthesis. It’s used temporarily relieves minor aches and pains due to: headache; the common cold; muscular aches; backache; toothache; minor pain of arthritis; menstrual cramps and temporarily reduces fever. The exact mechanism of action of ibuprofen is unknown. Ibuprofen is a non-selective inhibitor of cyclooxygenase, an enzyme invovled in prostaglandin synthesis via the arachidonic acid pathway. Its pharmacological effects are believed to be due to inhibition cylooxygenase-2 (COX-2) which decreases the synthesis of prostaglandins involved in mediating inflammation, pain, fever and swelling. Antipyretic effects may be due to action on the hypothalamus, resulting in an increased peripheral blood flow, vasodilation, and subsequent heat dissipation. Inhibition of COX-1 is thought to cause some of the side effects of ibuprofen including GI ulceration. Ibuprofen is administered as a racemic mixture. The R-enantiomer undergoes extensive interconversion to the S-enantiomer in vivo. The S-enantiomer is believed to be the more pharmacologically active enantiomer.

Dopamine, a sympathomimetic amine vasopressor, is the naturally occurring immediate precursor of norepinephrine. G protein-coupled dopamine receptors (D1, D2, D3, D4, and D5) mediate all of the physiological functions of the catecholaminergic neurotransmitter dopamine, ranging from voluntary movement and reward to hormonal regulation and hypertension. Dopamine HCl is indicated for the correction of hemodynamic imbalances present in the shock syndrome due to myocardial infarction, trauma, endotoxic septicemia, open-heart surgery, renal failure, and chronic cardiac decompensation as in congestive failure.

Metolazone is a thiazide-like diuretic marketed under the brand names Mykrox and Zaroxolyn. Zaroxolyn is indicated for the treatment of salt and water retention including: • Edema accompanying congestive heart failure; • Edema accompanying renal diseases including the nephrotic syndrome and states of diminished renal function. Zaroxolyn is also indicated for the treatment of hypertension, alone or in combination with other antihypertensive drugs of a different class. Metolazone is a quinazoline diuretic, with properties generally similar to the thiazide diuretics. The actions of Metolazone result from interference with the renal tubular mechanism of electrolyte reabsorption. Metolazone acts primarily to inhibit sodium reabsorption at the cortical diluting site and to a lesser extent in the proximal convoluted tubule. Sodium and chloride ions are excreted in approximately equivalent amounts. The increased delivery of sodium to the distal tubular exchange site results in increased potassium excretion. Metolazone does not inhibit carbonic anhydrase. A proximal action of Metolazone has been shown in humans by increased excretion of phosphate and magnesium ions and by a markedly increased fractional excretion of sodium in patients with severely compromised glomerular filtration. This action has been demonstrated in animals by micropuncture studies.