Miscellaneous

·         Geriatric patients loose PHASE 1 of metabolism first.

·         Iodine allergies reflect primarily the hyperosmolarity of the contrast agent with resultant non-IgE mediated mast cell degranulation.

Although shellfish may be rich in iodine, the reaction to shellfish is usually caused by IgE antibodies to the proteins in the fish and not the iodine.and they are not interrelated.

·         The warfarin dose should be decreased by half when amiodarone is started, with close monitoring of the INR owing to amiodarone's inhibition of warfarin metabolism.

·         Effects on thyroid function does interferon alpha-2B for hepatitis C infection haveBoth hypothyroidism and hyperthyroidism may be observed, and in most patients these abnormalities are transient, requiring treatment if symptomatic.

·         Drugs that have been associated with thrombocytopenia: Abciximab, ticlopidine, linezolid, heparin, isotretinoin, H2Ras, and trimethoprim.

·         In patients with hyperphosphatemia, calcium carbonate be taken with or directly before meals (calcium carbonate is more soluble at a lower gastric pH).

What calcium-containing product should not be used as a phosphate binder in patients with renal failure is Calcium citrate because it increases the risk of aluminum toxicity by increasing gastric absorption of aluminum.

·         Intravenous iron products do not require test dose before treatment are Iron sucrose and sodium ferric gluconate.

·         Diltiazem is often used in transplant patients to achieve desired cyclosporine levels with lower cyclosporine doses because it inhibits the hepatic elimination of cyclosporine and allows lower doses of cyclosporine to be used.

·         SULFONAMIDE CONTAINING DRUGS: Carbonic anhydrase inhibitors, all loop diuretics except ethacrynic acid, thiazides, sulfa antibiotics, celecoxib, phenothiazines, propylthiouracil, sulfonylureas,white wine

·         Concomitant use of linezolid and SSRIs may increase the risk of serotonin syndrome. The literature supports discontinuation of the serotonergic agent 2 weeks before starting linezolid.

Linezolid has monoamine oxidase inhibitory activity (albeit relatively weak compared with traditional MAO inhibitors).

·         Cholestyramine given 8 g three times a day for 11 days is recommended for all childbearing women stopping leflunomide, since up to 2 years may be required to reach undetectable levels of the active metabolite.

·         Methotrexate must be used in combination with infliximab for rheumatoid arthritis to minimize the formation of antibodies to infliximab.

·         ACE inhibitors increase the risk of Stevens-Johnson syndrome when given with allopurinol.

·         Activated charcoal, a fine, black powder with a high adsorptive capacity, is considered to be a highly valuable agent in the treatment of many kinds of drug poisoning. Drugs that are well adsorbed by activated charcoal include primaquine, propoxyphene, dextroamphetamine, chlorpheniramine, phenobarbital, carbamazepine, digoxin, and aspirin.

Mineral acids, alkalines, tolbutamide, and other drugs that are insoluble in acidic aqueous solution are not well adsorbed. Charcoal also does not bind Ca, lithium (Li), or Fe.

·         We manage cyanide poisoning first by dealing with the high reactivity of CN-with Fe(II) in hemoglobin and the subsequent formation of Fe(III) hemoglobin. We do that by first administering sodium nitrite (intravenously) to regenerate active cytochromes and convert hemoglobin to the more cyanide-reactive methemoglobin. Then we administer sodium thiosulfate to form the somewhat less toxic and more readily excreted thiocyanate.

·         Disodium EDTA (edetate sodium), a calcium chelator that is used to treat severe, acute hypercalcemia, causes hypocalcemic tetany on rapid IV administration. This effect is not observed on slow infusion (15 mg/min) because extracirculatory calcium stores are available and drawn upon to prevent a significant reduction in plasma calcium levels. When Ca-Na2EDTA is given IV (it is sometimes used to diagnose or treat lead poisoning), hypocalcemia does not develop, even when large doses are required.

·         Arsenic is a constituent of fungicides, herbicides, and pesticides. Symptoms of acute toxicity include tightness in the throat, difficulty in swallowing, and stomach pains. Projectile vomiting and severe diarrhea can lead to hypovolemic shock, significant electrolyte derangements, and death. Chronic poisoning may cause peripheral neuritis, anemia, skin keratosis, and capillary dilation leading to hypotension. Dimercaprol (British anti-Lewisite [BAL]) is the main antidote used for arsenic poisoning.

·         Most of the adverse responses to nerve gases (irreversible ACh esterase inhibitors such as soman and sarin) are due to a buildup of ACh at muscarinic receptors (i.e., ACh released from postganglionic parasympathetic nerves or sympathetic/cholinergic nerves innervating sweat glands). Those responses will be attenuated by atropine, because it is a highly specific competitive muscarinic antagonist. However, skeletal muscle stimulation (or eventual paralysis) involves nicotinic receptor activation. That will not be affected by atropine, and unless other supportive measures are provided, the patient is likely to die from ventilatory arrest/apnea.

·         Succimer (a more polar salt of dimercaprol; British anti-Lewisite; BAL)