What are the brand and generic names, dosage forms, pharmacologic categories, FDA-approved indications, dosage and frequency, mechanisms of action, contraindications, adverse effects, and drug interactions for Farxiga (dapagliflozin), Dyazide/Maxzide (triamterene/hydrochlorothiazide), Prometrium (progesterone), Seroquel (quetiapine), Invokana (canagliflozin), Aldactone (spironolactone), Provera (medroxyprogesterone), and Zyprexa (olanzapine)?

Comprehensive Medication Guide for Multiple Medications

Farxiga (dapagliflozin), Dyazide/Maxzide (triamterene/hydrochlorothiazide), Prometrium (progesterone), Seroquel (quetiapine), Invokana (canagliflozin), Aldactone (spironolactone), Provera (medroxyprogesterone), and Zyprexa (olanzapine) each have distinct pharmacological profiles that must be understood for proper clinical use.

Farxiga (dapagliflozin)

a. Brand and generic name: Farxiga (dapagliflozin)

b. Dosage forms: Oral tablets (5 mg, 10 mg)

c. Pharmacologic category: Sodium-glucose co-transporter 2 (SGLT2) inhibitor

d. FDA-approved indications:

• Type 2 diabetes mellitus
• Heart failure with reduced ejection fraction (HFrEF)
• Chronic kidney disease

e. Dosage and frequency:

• Diabetes: 10 mg once daily
• Heart failure: 10 mg once daily (target dose in clinical trials: 9.8 mg daily) 1

f. Mechanism of action: Inhibits SGLT2 in proximal renal tubules, reducing glucose reabsorption and increasing urinary glucose excretion

g. Contraindications:

• Severe renal impairment (eGFR <30 mL/min/1.73m²)
• Dialysis
• Type 1 diabetes
• Diabetic ketoacidosis

h. Adverse effects:

• Genital mycotic infections
• Urinary tract infections
• Volume depletion/hypotension
• Diabetic ketoacidosis
• Acute kidney injury

i. Drug interactions:

• No significant interactions with metformin, pioglitazone, glimepiride, or sitagliptin 2
• May enhance hypotensive effects of antihypertensives

j. Patient counseling points:

• Take once daily, with or without food
• Monitor for signs of urinary tract infections
• Stay hydrated
• Monitor blood glucose regularly
• Report symptoms of ketoacidosis (nausea, vomiting, abdominal pain)

Dyazide/Maxzide (triamterene/hydrochlorothiazide)

a. Brand and generic name: Dyazide/Maxzide (triamterene/hydrochlorothiazide)

b. Dosage forms:

• Dyazide: Capsules (37.5 mg triamterene/25 mg hydrochlorothiazide)
• Maxzide: Tablets (75 mg triamterene/50 mg hydrochlorothiazide) 3

c. Pharmacologic category: Combination diuretic (potassium-sparing + thiazide)

d. FDA-approved indications: Hypertension

e. Dosage and frequency:

• Dyazide: 1-2 capsules daily
• Maxzide: 1 tablet daily 3

f. Mechanism of action:

• Triamterene: Blocks sodium channels in distal tubule, reducing potassium excretion
• Hydrochlorothiazide: Inhibits sodium and chloride reabsorption in distal tubule

g. Contraindications:

• Hyperkalemia
• Severe renal impairment
• Anuria
• Concomitant use of other potassium-sparing diuretics or potassium supplements

h. Adverse effects:

• Hyperkalemia
• Hyponatremia
• Metabolic alkalosis
• Hyperuricemia
• Photosensitivity

i. Drug interactions:

• ACE inhibitors/ARBs (increased risk of hyperkalemia)
• NSAIDs (reduced diuretic efficacy)
• Lithium (increased lithium levels)
• Digoxin (increased risk of digitalis toxicity)

j. Patient counseling points:

• Take in the morning to avoid nighttime urination
• Monitor potassium levels
• Avoid potassium supplements unless prescribed
• Protect skin from sun exposure
• Report muscle weakness or cramps

Aldactone (spironolactone)

a. Brand and generic name: Aldactone (spironolactone)

b. Dosage forms: Oral tablets (25 mg, 50 mg, 100 mg)

c. Pharmacologic category: Potassium-sparing diuretic, mineralocorticoid receptor antagonist

d. FDA-approved indications:

• Heart failure
• Hypertension
• Primary aldosteronism
• Edema associated with hepatic cirrhosis
• Hypokalemia

e. Dosage and frequency:

• Heart failure: 12.5-25 mg once daily, target 25-50 mg once daily 1
• Hypertension: 25-100 mg daily in 1-2 divided doses 1

f. Mechanism of action: Competitively blocks aldosterone receptors, increasing sodium and water excretion while conserving potassium

g. Contraindications:

• Hyperkalemia
• Anuria
• Severe renal impairment
• Addison's disease

h. Adverse effects:

• Hyperkalemia
• Gynecomastia
• Menstrual irregularities
• Impotence
• Metabolic acidosis

i. Drug interactions:

• ACE inhibitors/ARBs (increased risk of hyperkalemia)
• Potassium supplements (increased risk of hyperkalemia)
• NSAIDs (reduced diuretic efficacy)
• Digoxin (altered digoxin levels)

j. Patient counseling points:

• Regular monitoring of potassium levels
• May take with food to reduce GI upset
• Report breast tenderness or enlargement
• Avoid potassium supplements unless prescribed
• May take several weeks for full effect in heart failure

Seroquel (quetiapine)

a. Brand and generic name: Seroquel (quetiapine)

b. Dosage forms:

• Immediate-release tablets (25 mg, 50 mg, 100 mg, 200 mg, 300 mg, 400 mg)
• Extended-release tablets (50 mg, 150 mg, 200 mg, 300 mg, 400 mg)

c. Pharmacologic category: Atypical antipsychotic

d. FDA-approved indications:

• Schizophrenia
• Bipolar disorder (manic, depressive, maintenance)
• Adjunctive treatment for major depressive disorder

e. Dosage and frequency:

• Schizophrenia: 150-750 mg/day divided doses (IR) or once daily (XR)
• Bipolar mania: 400-800 mg/day
• Bipolar depression: 300 mg/day
• Major depressive disorder (adjunct): 150-300 mg/day

f. Mechanism of action: Antagonism of multiple neurotransmitter receptors including serotonin 5-HT2A and dopamine D2 receptors

g. Contraindications:

• Hypersensitivity to quetiapine

h. Adverse effects:

• Sedation/somnolence
• Weight gain
• Metabolic effects (hyperglycemia, hyperlipidemia)
• Orthostatic hypotension
• QT prolongation
• Extrapyramidal symptoms (less common than typical antipsychotics)

i. Drug interactions:

• CYP3A4 inhibitors (increased quetiapine levels) 4
• CYP3A4 inducers (decreased quetiapine levels)
• CNS depressants (enhanced sedative effects)
• Antihypertensives (enhanced hypotensive effects)

j. Patient counseling points:

• May cause drowsiness; use caution when driving
• Take as prescribed, do not abruptly discontinue
• Regular monitoring of weight, blood glucose, and lipids
• Rise slowly from sitting/lying position to minimize orthostatic hypotension
• Avoid alcohol

Invokana (canagliflozin)

a. Brand and generic name: Invokana (canagliflozin)

b. Dosage forms: Oral tablets (100 mg, 300 mg)

c. Pharmacologic category: Sodium-glucose co-transporter 2 (SGLT2) inhibitor

d. FDA-approved indications:

• Type 2 diabetes mellitus
• Diabetic kidney disease
• Reducing risk of cardiovascular events in type 2 diabetes with established cardiovascular disease

e. Dosage and frequency: 100-300 mg once daily

f. Mechanism of action: Inhibits SGLT2 in proximal renal tubules, reducing glucose reabsorption and increasing urinary glucose excretion

g. Contraindications:

• Severe renal impairment (eGFR <30 mL/min/1.73m²)
• Dialysis
• Type 1 diabetes
• Diabetic ketoacidosis

h. Adverse effects:

• Genital mycotic infections
• Urinary tract infections
• Volume depletion/hypotension
• Diabetic ketoacidosis
• Increased risk of lower limb amputations
• Bone fracture risk

i. Drug interactions:

• Diuretics (enhanced volume depletion)
• UGT enzyme inducers (decreased canagliflozin levels)
• Digoxin (increased digoxin levels)

j. Patient counseling points:

• Take before first meal of the day
• Monitor for signs of urinary/genital infections
• Stay hydrated
• Monitor blood glucose regularly
• Report foot problems promptly
• Report symptoms of ketoacidosis

Prometrium (progesterone)

a. Brand and generic name: Prometrium (progesterone)

b. Dosage forms: Oral capsules (100 mg, 200 mg)

c. Pharmacologic category: Progestin hormone

d. FDA-approved indications:

• Prevention of endometrial hyperplasia in postmenopausal women receiving estrogen therapy
• Secondary amenorrhea

e. Dosage and frequency:

• Endometrial hyperplasia prevention: 200 mg daily in the evening for 12 days per month
• Secondary amenorrhea: 400 mg daily in the evening for 10 days

f. Mechanism of action: Binds to progesterone receptors, converting proliferative endometrium to secretory endometrium

g. Contraindications:

• Known hypersensitivity to progesterone
• Undiagnosed vaginal bleeding
• Liver disease
• Known or suspected breast cancer
• Active or history of thromboembolic disorders

h. Adverse effects:

• Drowsiness/dizziness
• Headache
• Breast tenderness
• Mood changes
• Abdominal cramping
• Nausea

i. Drug interactions:

• CYP3A4 inducers (decreased progesterone levels)
• CYP3A4 inhibitors (increased progesterone levels)

j. Patient counseling points:

• Take at bedtime due to sedative effects
• May cause dizziness; use caution when driving
• Use with estrogen therapy as directed
• Report unusual vaginal bleeding
• Report symptoms of blood clots (leg pain, chest pain, shortness of breath)

Provera (medroxyprogesterone)

a. Brand and generic name: Provera (medroxyprogesterone acetate)

b. Dosage forms: Oral tablets (2.5 mg, 5 mg, 10 mg)

c. Pharmacologic category: Synthetic progestin

d. FDA-approved indications:

• Secondary amenorrhea
• Abnormal uterine bleeding due to hormonal imbalance
• Endometrial hyperplasia prevention in postmenopausal women receiving estrogen therapy

e. Dosage and frequency:

• Secondary amenorrhea: 5-10 mg daily for 5-10 days
• Abnormal uterine bleeding: 5-10 mg daily for 5-10 days
• Endometrial hyperplasia prevention: 5-10 mg daily for 12-14 days per month

f. Mechanism of action: Binds to progesterone receptors, converting proliferative endometrium to secretory endometrium

g. Contraindications:

• Known hypersensitivity to medroxyprogesterone
• Undiagnosed vaginal bleeding
• Liver disease
• Known or suspected breast cancer
• History of thromboembolic disorders
• Pregnancy

h. Adverse effects:

• Weight gain 1
• Fluid retention
• Breakthrough bleeding
• Headache
• Mood changes
• Breast tenderness

i. Drug interactions:

• Aminoglutethimide (decreased medroxyprogesterone levels)
• CYP3A4 inducers (decreased medroxyprogesterone levels)

j. Patient counseling points:

• Take as directed
• May cause weight gain
• Report unusual vaginal bleeding
• Report symptoms of blood clots
• Not for use as contraception (oral form)
• May affect menstrual cycle

Zyprexa (olanzapine)

a. Brand and generic name: Zyprexa (olanzapine)

b. Dosage forms:

• Tablets (2.5 mg, 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg)
• Orally disintegrating tablets (Zyprexa Zydis): 5 mg, 10 mg, 15 mg, 20 mg
• Intramuscular injection: 10 mg vial 5

c. Pharmacologic category: Atypical antipsychotic

d. FDA-approved indications:

• Schizophrenia
• Bipolar disorder (manic/mixed episodes)
• Treatment-resistant depression (with fluoxetine) 5

e. Dosage and frequency:

• Schizophrenia: 5-20 mg once daily
• Bipolar mania: 10-20 mg once daily
• Treatment-resistant depression (with fluoxetine): 5-20 mg olanzapine with 20-50 mg fluoxetine once daily 5

f. Mechanism of action: Antagonism of multiple neurotransmitter receptors including serotonin 5-HT2A and dopamine D2 receptors

g. Contraindications:

• Hypersensitivity to olanzapine

h. Adverse effects:

• Significant weight gain
• Metabolic effects (hyperglycemia, hyperlipidemia, diabetes)
• Sedation
• Orthostatic hypotension
• Increased risk of cerebrovascular events in elderly patients with dementia
• Extrapyramidal symptoms (less common than typical antipsychotics)

i. Drug interactions:

• CYP1A2 inhibitors (increased olanzapine levels) 4
• CYP1A2 inducers (decreased olanzapine levels)
• CNS depressants (enhanced sedative effects)
• Smoking (decreased olanzapine levels) 4

j. Patient counseling points:

• May cause drowsiness; use caution when driving
• Take as prescribed, do not abruptly discontinue
• Regular monitoring of weight, blood glucose, and lipids
• Rise slowly from sitting/lying position to minimize orthostatic hypotension
• Report significant weight gain or increased thirst/urination
• Avoid alcohol