The 3170 V pill is a Furosemide 40 mg tablet manufactured by Qualitest Pharmaceuticals (now Vintage Pharmaceuticals / Endo International). Furosemide is a potent loop diuretic (commonly known by the brand name Lasix) used to treat fluid retention and hypertension. It is not a controlled substance.
Pill Identification & Physical Characteristics
Property – Description
- Active Ingredient – Furosemide (40 mg)
- Imprint –
3170overV(scored) on one side; plain on the reverse - Shape & Color – Round; White to off-white
- Size – Approximately 8 mm in diameter
- Drug Class – Loop Diuretic / Sulfonamide Derivative
- Manufacturer / Labeler – Qualitest Pharmaceuticals / Vintage Pharmaceuticals
Mechanism of Action
Furosemide inhibits electrolyte reabsorption in the renal tubules:
- Cotransporter Inhibition: It reversibly blocks the luminal (NKCC2) cotransporter in the thick ascending limb of the loop of Henle.
- Increased Solute and Water Excretion: By inhibiting the reabsorption of sodium , potassium ,and chloride , it abolishes the corticomedullary osmotic gradient, preventing water reabsorption. This causes substantial excretion of water, sodium, chloride, magnesium, and calcium.
- Hemodynamic Effects: Furosemide also stimulates renal prostaglandin synthesis, promoting acute renal vasodilation, reducing renal vascular resistance, and lowering left ventricular filling pressures (preload) even before diuresis begins.
Indications & Dosage
Clinical Indications
- Edema: Management of fluid retention associated with congestive heart failure, hepatic cirrhosis (ascites), and renal disease (including nephrotic syndrome).
- Hypertension: Monotherapy or in combination with other antihypertensive agents for blood pressure control.
- Hypercalcemia: Adjunctive management in acute hypercalcemic crises.
General Adult Dosing
- Edema Management: Typically initiated at 20 mg to 80 mg as a single oral dose, preferably taken in the morning to avoid nighttime urination (nocturia). If needed, the dose may be titrated upward by 20 mg to 40 mg every 6 to 8 hours until the desired diuretic response is obtained. Maintenance dosing can be once or twice daily.
- Hypertension: Usually started at 40 mg twice daily. Dosage adjustments are made according to blood pressure response.
- Administration: Swallow whole with water. Can be taken with or without food, though food slightly reduces bioavailability without significantly altering the clinical diuretic effect.
Side Effects
Common Adverse Reactions
- Increased urination frequency and volume
- Dizziness, lightheadedness, and orthostatic hypotension (drop in blood pressure when standing)
- Dehydration and dry mouth
- Electrolyte imbalances (hypokalemia, hyponatremia, hypomagnesemia, hypocalcemia)
- Hyperuricemia (can trigger acute gout attacks)
- Mild gastrointestinal upset (nausea, cramping)
Severe & Emergent Adverse Reactions
- Severe Hypokalemia: Cardiac arrhythmias, muscle weakness, severe cramps, or tetany.
- Ototoxicity: Tinnitus, vertigo, or reversible/permanent hearing impairment (higher risk at high doses or combined with aminoglycosides).
- Acute Kidney Injury (Prerenal Azotemia): Profound volume depletion leading to renal hypoperfusion and elevated BUN/creatinine.
- Hypersensitivity Reactions: Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), or systemic vasculitis (cross-reactivity can occur in individuals with severe sulfonamide allergies).
Precautions & Drug Interactions
- Digoxin / Cardiac Glycosides: Furosemide-induced hypokalemia and hypomagnesemia substantially increase the risk of digitalis toxicity and fatal cardiac arrhythmias. Potassium levels must be monitored closely.
- Ototoxic and Nephrotoxic Drugs: Co-administration with aminoglycoside antibiotics (e.g., gentamicin), vancomycin, or platinum-based chemotherapies (e.g., cisplatin) potentiates the risk of irreversible ear and kidney damage.
- Nonsteroidal Anti-inflammatory Drugs (NSAIDs): NSAIDs (e.g., ibuprofen, naproxen) inhibit renal prostaglandins, blunting furosemide’s diuretic and antihypertensive efficacy while increasing acute renal failure risk.
- Lithium: Loop diuretics reduce renal clearance of lithium, leading to elevated serum lithium concentrations and acute lithium toxicity.
- Anuria: Furosemide is strictly contraindicated in patients with anuria (complete cessation of urine production) or uncorrected severe electrolyte depletion and hepatic coma.
Black Box Warning
- FDA Boxed Warning — Profound Diuresis & Electrolyte Depletion:
- Potent Diuretic Effect: Furosemide is an extremely potent diuretic. Administration in excessive amounts can lead to profound diuresis with water and electrolyte depletion.
- Required Monitoring: Careful medical supervision is required. Dose and schedule must be adjusted to individual patient requirements with routine monitoring of serum electrolytes (potassium, sodium, magnesium), BUN, and creatinine.