Amitriptyline is a derivative of dibenzocycloheptadiene and a tricyclic antidepressant (TCA) and is mainly used to treat symptoms of depression. It works on the central nervous system (CNS) by inhibiting the membrane pump mechanism responsible for uptake of norepinephrine and serotonin in adrenergic and serotonergic neurons. Amitriptyline has been frequently used as an active comparator in clinical trials on newer antidepressants. It is rarely used as a first-line antidepressant nowadays due to its high degree of toxicity in overdose and generally poorer tolerability than the newer antidepressants.

Medroxyprogesterone acetate (INN, USAN, BAN), also known as 17α-hydroxy-6α-methylprogesterone acetate, and commonly abbreviated as MPA, is a steroidal progestin, a synthetic variant of the human hormone progesterone. Medroxyprogesterone acetate (MPA) administered orally or parenterally in the recommended doses to women with adequate endogenous estrogen, transforms proliferative into secretory endometrium. Androgenic and anabolic effects have been noted, but the drug is apparently devoid of significant estrogenic activity. While parenterally administered MPA inhibits gonadotropin production, which in turn prevents follicular maturation and ovulation, available data indicate that this does not occur when the usually recommended oral dosage is given as single daily doses. MPA is a more potent derivative of its parent compound medroxyprogesterone (MP). While medroxyprogesterone is sometimes used as a synonym for medroxyprogesterone acetate, what is normally being administered is MPA and not MP. Used as a contraceptive and to treat secondary amenorrhea, abnormal uterine bleeding, pain associated with endometriosis, endometrial and renal cell carcinomas, paraphilia in males, GnRH-dependent forms of precocious puberty, as well as to prevent endometrial changes associated with estrogens. Progestins diffuse freely into target cells in the female reproductive tract, mammary gland, hypothalamus, and the pituitary and bind to the progesterone receptor. Once bound to the receptor, progestins slow the frequency of release of gonadotropin releasing hormone (GnRH) from the hypothalamus and blunt the pre-ovulatory LH surge.

Like other thiazides, chlorothiazide promotes water loss from the body (diuretics). It inhibits Na /Cl- reabsorption from the distal convoluted tubules in the kidneys. Thiazides also cause loss of potassium and an increase in serum uric acid. Thiazides are often used to treat hypertension, but their hypotensive effects are not necessarily due to their diuretic activity. Thiazides have been shown to prevent hypertension-related morbidity and mortality although the mechanism is not fully understood. Thiazides cause vasodilation by activating calcium-activated potassium channels (large conductance) in vascular smooth muscles and inhibiting various carbonic anhydrases in vascular tissue. Chlorothiazide affects the distal renal tubular mechanism of electrolyte reabsorption. At maximal therapeutic dosages, all thiazides are approximately equal in their diuretic efficacy. Chlorothiazide increases excretion of sodium and chloride in approximately equivalent amounts. Natriuresis may be accompanied by some loss of potassium and bicarbonate. After oral doses, 10-15 percent of the dose is excreted unchanged in the urine. Chlorothiazide crosses the placental but not the blood-brain barrier and is excreted in breast milk. As a diuretic, chlorothiazide inhibits active chloride reabsorption at the early distal tubule via the Na-Cl cotransporter, resulting in an increase in the excretion of sodium, chloride, and water. Thiazides like chlorothiazide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. This results in an increase in potassium excretion via the sodium-potassium exchange mechanism. The antihypertensive mechanism of chlorothiazide is less well understood although it may be mediated through its action on carbonic anhydrases in the smooth muscle or through its action on the large-conductance calcium-activated potassium (KCa) channel, also found in the smooth muscle. It is marketed under the brand name Diuril.

Like other thiazides, chlorothiazide promotes water loss from the body (diuretics). It inhibits Na /Cl- reabsorption from the distal convoluted tubules in the kidneys. Thiazides also cause loss of potassium and an increase in serum uric acid. Thiazides are often used to treat hypertension, but their hypotensive effects are not necessarily due to their diuretic activity. Thiazides have been shown to prevent hypertension-related morbidity and mortality although the mechanism is not fully understood. Thiazides cause vasodilation by activating calcium-activated potassium channels (large conductance) in vascular smooth muscles and inhibiting various carbonic anhydrases in vascular tissue. Chlorothiazide affects the distal renal tubular mechanism of electrolyte reabsorption. At maximal therapeutic dosages, all thiazides are approximately equal in their diuretic efficacy. Chlorothiazide increases excretion of sodium and chloride in approximately equivalent amounts. Natriuresis may be accompanied by some loss of potassium and bicarbonate. After oral doses, 10-15 percent of the dose is excreted unchanged in the urine. Chlorothiazide crosses the placental but not the blood-brain barrier and is excreted in breast milk. As a diuretic, chlorothiazide inhibits active chloride reabsorption at the early distal tubule via the Na-Cl cotransporter, resulting in an increase in the excretion of sodium, chloride, and water. Thiazides like chlorothiazide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. This results in an increase in potassium excretion via the sodium-potassium exchange mechanism. The antihypertensive mechanism of chlorothiazide is less well understood although it may be mediated through its action on carbonic anhydrases in the smooth muscle or through its action on the large-conductance calcium-activated potassium (KCa) channel, also found in the smooth muscle. It is marketed under the brand name Diuril.

Acquired myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction, characterized clinically by muscle weakness and abnormal fatigability on exertion. Current guidelines and recommendations for MG treatment are based largely on clinical experience, retrospective analyses and expert consensus. Pyridostigmine (under the trade names Mestinon (Valeant Pharmaceuticals)), has been used as a treatment for MG for over 50 years and is generally considered safe. It is suitable as a long-term treatment in patients with generalized non-progressive milder disease, and as an adjunctive therapy in patients with severe disease who are also receiving immunotherapy. Pyridostigmine inhibits acetylcholinesterase in the synaptic cleft by competing with acetylcholine for attachment to acetylcholinesterase, thus slowing down the hydrolysis of acetylcholine, and thereby increases efficiency of cholinergic transmission in the neuromuscular junction and prolongs the effects of acetylcholine. The side effects of Mestinon are most commonly related to over dosage and generally are of two varieties, muscarinic and nicotinic. Among those in the former group are nausea, vomiting, diarrhea, abdominal cramps, increased peristalsis, increased salivation, increased bronchial secretions, miosis and diaphoresis. Nicotinic side effects are comprised chiefly of muscle cramps, fasciculation and weakness. Muscarinic side effects can usually be counteracted by atropine, but for reasons shown in the preceding section the expedient is not without danger. As with any compound containing the bromide radical, a skin rash may be seen in an occasional patient. Such reactions usually subside promptly upon discontinuance of the medication.

Acquired myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction, characterized clinically by muscle weakness and abnormal fatigability on exertion. Current guidelines and recommendations for MG treatment are based largely on clinical experience, retrospective analyses and expert consensus. Pyridostigmine (under the trade names Mestinon (Valeant Pharmaceuticals)), has been used as a treatment for MG for over 50 years and is generally considered safe. It is suitable as a long-term treatment in patients with generalized non-progressive milder disease, and as an adjunctive therapy in patients with severe disease who are also receiving immunotherapy. Pyridostigmine inhibits acetylcholinesterase in the synaptic cleft by competing with acetylcholine for attachment to acetylcholinesterase, thus slowing down the hydrolysis of acetylcholine, and thereby increases efficiency of cholinergic transmission in the neuromuscular junction and prolongs the effects of acetylcholine. The side effects of Mestinon are most commonly related to over dosage and generally are of two varieties, muscarinic and nicotinic. Among those in the former group are nausea, vomiting, diarrhea, abdominal cramps, increased peristalsis, increased salivation, increased bronchial secretions, miosis and diaphoresis. Nicotinic side effects are comprised chiefly of muscle cramps, fasciculation and weakness. Muscarinic side effects can usually be counteracted by atropine, but for reasons shown in the preceding section the expedient is not without danger. As with any compound containing the bromide radical, a skin rash may be seen in an occasional patient. Such reactions usually subside promptly upon discontinuance of the medication.

Acquired myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction, characterized clinically by muscle weakness and abnormal fatigability on exertion. Current guidelines and recommendations for MG treatment are based largely on clinical experience, retrospective analyses and expert consensus. Pyridostigmine (under the trade names Mestinon (Valeant Pharmaceuticals)), has been used as a treatment for MG for over 50 years and is generally considered safe. It is suitable as a long-term treatment in patients with generalized non-progressive milder disease, and as an adjunctive therapy in patients with severe disease who are also receiving immunotherapy. Pyridostigmine inhibits acetylcholinesterase in the synaptic cleft by competing with acetylcholine for attachment to acetylcholinesterase, thus slowing down the hydrolysis of acetylcholine, and thereby increases efficiency of cholinergic transmission in the neuromuscular junction and prolongs the effects of acetylcholine. The side effects of Mestinon are most commonly related to over dosage and generally are of two varieties, muscarinic and nicotinic. Among those in the former group are nausea, vomiting, diarrhea, abdominal cramps, increased peristalsis, increased salivation, increased bronchial secretions, miosis and diaphoresis. Nicotinic side effects are comprised chiefly of muscle cramps, fasciculation and weakness. Muscarinic side effects can usually be counteracted by atropine, but for reasons shown in the preceding section the expedient is not without danger. As with any compound containing the bromide radical, a skin rash may be seen in an occasional patient. Such reactions usually subside promptly upon discontinuance of the medication.

Acquired myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction, characterized clinically by muscle weakness and abnormal fatigability on exertion. Current guidelines and recommendations for MG treatment are based largely on clinical experience, retrospective analyses and expert consensus. Pyridostigmine (under the trade names Mestinon (Valeant Pharmaceuticals)), has been used as a treatment for MG for over 50 years and is generally considered safe. It is suitable as a long-term treatment in patients with generalized non-progressive milder disease, and as an adjunctive therapy in patients with severe disease who are also receiving immunotherapy. Pyridostigmine inhibits acetylcholinesterase in the synaptic cleft by competing with acetylcholine for attachment to acetylcholinesterase, thus slowing down the hydrolysis of acetylcholine, and thereby increases efficiency of cholinergic transmission in the neuromuscular junction and prolongs the effects of acetylcholine. The side effects of Mestinon are most commonly related to over dosage and generally are of two varieties, muscarinic and nicotinic. Among those in the former group are nausea, vomiting, diarrhea, abdominal cramps, increased peristalsis, increased salivation, increased bronchial secretions, miosis and diaphoresis. Nicotinic side effects are comprised chiefly of muscle cramps, fasciculation and weakness. Muscarinic side effects can usually be counteracted by atropine, but for reasons shown in the preceding section the expedient is not without danger. As with any compound containing the bromide radical, a skin rash may be seen in an occasional patient. Such reactions usually subside promptly upon discontinuance of the medication.

Primidone is an anticonvulsant of the barbiturate class. It was introduced in 1954 under the brand name Mysoline by Wyeth in the United States. Mysoline, used alone or concomitantly with other anticonvulsants, is indicated in the control of grand mal, psychomotor, and focal epileptic seizures. It may control grand mal seizures refractory to other anticonvulsant therapy. Mysoline raises electro- or chemoshock seizure thresholds or alters seizure patterns in experimental animals. The mechanism(s) of primidone’s antiepileptic action is not known. Primidone per se has anticonvulsant activity, as do its two metabolites, phenobarbital and phenylethylmalonamide (PEMA). In addition to its anticonvulsant activity, PEMA potentiates the anticonvulsant activity of phenobarbital in experimental animals. Primidone itself doesn’t act on GABA-A receptors. It is active metabolite - phenobarbital primary acts via modulation of GABA -A receptors. The most frequently occurring early side effects are ataxia and vertigo. These tend to disappear with continued therapy, or with reduction of initial dosage. Occasionally, the following have been reported: nausea, anorexia, vomiting, fatigue, hyperirritability, emotional disturbances, sexual impotency, diplopia, nystagmus, drowsiness, and morbilliform skin eruptions.Granulocytopenia, agranulocytosis, and red-cell hypoplasia and aplasia, have been reported rarely. These and, occasionally, other persistant or severe side effects may necessitate withdrawal of the drug. Megaloblastic anemia may occur as a rare idiosyncrasy to Mysoline and to other anticonvulsants. The anemia responds to folic acid without necessity of discontinuing medication.

Warfarin is an anticoagulant drug normally used to prevent blood clot formation as well as migration. Warfarin is marketed under the brand name Coumadin among others. Coumadin (crystalline warfarin sodium) is an anticoagulant which acts by inhibiting vitamin K-dependent coagulation factors. Chemically, it is 3-(α-acetonylbenzyl)-4-hydroxycoumarin and is a racemic mixture of the R- and S-enantiomers. Coumadin is indicated for the prophylaxis and/or treatment of venous thrombosis and its extension, and pulmonary embolism. It is also indicated for the prophylaxis and/or treatment of the thromboembolic complications associated with atrial fibrillation and/or cardiac valve replacement. Warfarin is thought to interfere with clotting factor synthesis by inhibition of the C1 subunit of the vitamin K epoxide reductase (VKORC1) enzyme complex, thereby reducing the regeneration of vitamin K1 epoxide. The degree of depression is dependent upon the dosage administered and, in part, by the patient’s VKORC1 genotype. Therapeutic doses of warfarin decrease the total amount of the active form of each vitamin K dependent clotting factor made by the liver by approximately 30% to 50%.