Most Used 8 Calcium Channel Blockers: Action Uses Dosage Side Effect

 Lasix Furosemide Loop diuretic

PHARMACOTHERAPEUTIC: Loop diuretic.

CLINICAL: Diuretic

 BLACK BOX ALERT  Large amounts can lead to a profound diuresis with water and electrolyte depletion.

Action Lasix/Furosemide

Enhances excretion of sodium, chloride, potassium by direct action at ascending limb of loop of Henle. Therapeutic Effect: Produces diuresis, lowers B/P.

Uses Lasix/Furosemide

Treatment of oedema associated with HF and renal/hepatic disease; acute pulmonary oedema. Treatment of hypertension (not recommended as initial treatment).

Precautions During Lasix/Furosemide

Contraindications: Hypersensitivity to furosemide. Anuria. Cautions: Hepatic cirrhosis, hepatic coma, severe electrolyte depletion, prediabetes, diabetes, systemic lupus erythematosus. Pts with prostatic hyperplasia/urinary stricture.

Most Used 8 Calcium Channel Blockers: Action Uses Dosage Side Effect

Route: PO

Onset: 30–60 min

Peak:1–2 hrs

Duration: 6–8 hrs

Route: IV

Onset: 5 min

Peak: 20–60 min

Duration: 2 hrs

Route: IM

Onset: 30 min

Peak: N/A

Duration: N/A

Moderately absorbed from GI tract. Protein binding: greater than 98%. Partially metabolized in liver. Primarily excreted in urine (nonrenal clearance increases in severe renal impairment). Not removed by hemodialysis. Half-life: 30–90 min (increased in renal/hepatic impairment, neonates).

Lifespan considerations

Pregnancy/Lactation: Crosses placenta. Distributed in breast milk. Children: Half-life increased in neonates; may require increased dosage interval. Elderly: Maybe more sensitive to hypotensive, electrolyte effects, developing circulatory collapse, thromboembolic effect. Age-related renal impairment may require dosage adjustment.

Interactions

DRUG: Amphotericin B, nephrotoxic ototoxic medications (e.g., lisinopril, IV contrast dye, vancomycin) may increase risk of nephrotoxicity, ototoxicity. May increase risk of lithium toxicity. Other medications causing hypokalemia (e.g., HCTZ, laxatives) may increase risk of hypokalemia. HERBAL: Ephedra, ginseng, Yohimbe may worsen hypertension. Garlic may increase antihypertensive effects. FOOD: None known. LAB VALUES: May increase serum glucose, BUN, uric acid. May decrease serum calcium, chloride, magnesium, potassium, sodium.

Availability (Rx)

Injection Solution: 10 mg/mL. Oral Solution: 10 mg/mL, 40 mg/5 mL.

Tablets: 20 mg, 40 mg, 80 mg.

Administration/handling

IV

Rate of Administration

May give undiluted but is compatible with D5W or 0.9% NaCl.

May be diluted for infusion to 1–2 mg/mL (maximum: 10 mg/mL).

Administer each 40 mg or fraction by IV push over 1–2 min. Do not exceed administration rate of 4 mg/min for short-term intermittent infusion.

PO

 Administer on empty stomach.

Give with food to avoid GI upset, preferably with breakfast (may prevent nocturia).

Food may decrease the diuretic effect.

Pneumothorax (collapsed lung): Treatment Types Symptoms Complications

Indications/routes/dosage  of Lasix/Furosemide

Oedema, HF

PO:ADULTS, ELDERLY: Initially, 20–80 mg/dose; may increase by 20–40 mg/dose q6–8h. May titrate up to 600 mg/day in severe edematous states.

CHILDREN: Initially, 2 mg/kg/dose. May increase by 1–2 mg/kg/dose at 6–8 hr intervals. Maximum: 6 mg/kg/dose. NEONATES: 1 mg/kg/dose 1–2 times/day.

IV, IM:ADULTS, ELDERLY: 20–40 mg/dose; may increase by 20 mg/dose q1–2h. Maximum single dose: 160–200 mg.

CHILDREN: Initially, 1 mg/kg/dose. May increase by 1 mg/kg/dose no sooner than 2 hrs after previous dose. Maximum: 6 mg/kg/dose. NEONATES: 1–2 mg/kg/dose q12–24h.

IV Infusion:ADULTS, ELDERLY: Loading dose bolus of 40–100 mg over 1–2 min, followed by infusion of 10–40 mg/hr; repeat loading dose before increasing infusion rate. Maximum: 80–160 mg/hr.

CHILDREN: 0.05 mg/kg/hr; titrate to desired effect. NEONATES: Initially, 0.2 mg/kg/hr. May increase by 0.1 mg/kg/hr q12–24h. Maximum: 0.4 mg/kg/hr.

Hypertension

PO: ADULTS, ELDERLY: 40 mg twice daily

Dosage in Renal Impairment: Avoid use in oliguric states.

Dosage in Hepatic Impairment

No dose adjustment. Decreased effect, increased sensitivity to hypokalemia/volume depletion in cirrhosis.

Side effects of Lasix/Furosemide

Expected: Increased urinary frequency/volume. Frequent: Nausea, dyspepsia, abdominal cramps, diarrhoea or constipation, electrolyte disturbances.Occasional: Dizziness, light-headedness, headache, blurred vision, paresthesia, photosensitivity, rash, fatigue, bladder spasm, restlessness, diaphoresis. Rare: Flank pain.

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Adverse effects/toxic reactions

Vigorous diuresis may lead to profound water loss/electrolyte depletion, resulting in hypokalemia, hyponatremia, dehydration. Sudden volume depletion. may result in increased risk of thrombosis, circulatory collapse, sudden death. Acute hypotensive episodes may occur, sometimes several days after beginning therapy. Ototoxicity (deafness, vertigo, tinnitus) may occur, esp. in pts with severe renal impairment. Can exacerbate diabetes mellitus, systemic lupus erythematosus, gout, pancreatitis. Blood dyscrasias have been reported.

Nursing considerations for Lasix/Furosemide

Baseline assessment

Check vital signs, esp. B/P, pulse, for hypotension before administration. Assess baseline renal function, serum electrolytes, esp. serum sodium, potassium. Assess skin turgor, mucous membranes for hydration status; observe for edema. Assess muscle strength, mental status. Note skin temperature, moisture. Obtain baseline weight. Initiate I&O monitoring. Auscultate lung sounds. In pts with hepatic cirrhosis and ascites, consider giving initial doses in a hospital setting.

Intervention/evaluation

Monitor B/P, vital signs, serum electrolytes, I&O, weight. Note extent of diuresis. Watch for symptoms of electrolyte imbalance: Hypokalemia may result in changes in muscle strength, tremor, muscle cramps, altered mental status, cardiac arrhythmias; hyponatremia may result in confusion, thirst, cold/clammy skin. Consider potassium supplementation if hypokalemia occurs.