Question

Choose a disorder of the Immune System and a drug therapy to treat it. Detail the drug, side effects, drug-drug interactions, food-drug interactions, and any teaching needed for the patient.

PLEASE BE DESCRIPTIVE AND ANSWER EVERY QUESTION. PLEASE CITE YOUR SOURCE

Answer 1

DEXAMETHASONE FOR MYASTHENIA GRAVIS

DRUG DETAIL

1. It is used systematically and locally in a wide variety of chronic disease like inflammatory disorders, auto-immune disorders, allergic, hematologic and neoplastic disorders.

2. Action of dexamethasone- It suppresses the inflammatory and normal immune response; have minimal mineralocorticoid (sodium retaining) activity.

PHARMACOKINETICS

- Absorption: well-absorbed after oral administration and absorption from the local site is slow but complete.

- Distribution: widely distributed and also crosses placenta or probably enters breastmilk.

- Metabolic and excretion: metabolised by the liver to inactivate metabolites.

- Half-life: 3 - 4.5 hrs (plasma), 36 - 54 hr (tissue)

ROUTE AND DOSAGE

PO, IM, IV (adults) - anti-inflammatory: 0.75 - 9 mg

airway edema or exturbation: 0.5 - 2 mg/kg/day

cerebral edema: 10mg IV

PO, IM, IV (children) - airway edema or exturbation: 0.5 - 2 mg/kg/day

anti-inflammatory: 0.08-0.3 mg/kg/day

physiologic replacement: 0.03 - 0.15 mg/kg/day

SIDE-EFFECTS

CNS- depression, headache, elevated intracranial pressure (in children), personality changes, euphoria, psychosis, restlessness.

EENT- increased intraocular pressure, cataract

CV- hypertension

GI- peptic ulcer, anorexia, nausea, vomiting

Derm- acne, wound healing, hirsutism, petechiae, fragility

Fluid and Electrolyte- fluid retention

Metabolism- weight gain

Hemat- thromboembolism, thrombophlebitis

Endo- adrenal reabsorption, hyperglycemia

Misc- cushingoid appearance, susceptibility to infection

DRUG-TO-DRUG INTERACTION

-Increased risk of digoxin toxicity due to hypokalemia that is caused by dexamethasone with thiazide and loop diuretics.

-Phenytoin, phenobarbital and rifampin cause an increase in metabolism.

-Hormonal contraceptives can cause a decrease in metabolism.

-There is an increased risk of adverse effects in GI with NSAIDs.

-There is a high risk of adverse reactions from the live-virus vaccine.

DRUG TO FOOD INTERACTION

Grapefruit juice causes an elevated serum level and effects budesonide.

PATIENT/ FAMILY TEACHING

- Instruct patients for right way for the administration of medication as directed.

- Take missed dose ASAP unless almost time for next dose.

- Never double the dosage.

- Restriction of medication suddenly can cause severe side effects like adrenal insufficiency.

- Instruct to avoid people with the known contagious disease or infection strictly.

- Vaccination only after consultation of medical professionals

- Advice for the follow-up to assess side-effects and adverse reaction.