DILTIAZEM HYDROCHLORIDE IN 0.72% SODIUM CHLORIDE
Clinical safety rating
safeNo significant drug interactions Can cause hypernatremia and fluid overload.
Diltiazem inhibits calcium ion influx across cardiac and vascular smooth muscle cell membranes by binding to the L-type calcium channels, leading to coronary vasodilation, decreased myocardial contractility, and slowed AV nodal conduction.
| Metabolism | Extensively metabolized in the liver via CYP3A4; undergoes deacetylation, N-demethylation, and O-demethylation; metabolites include desacetyl-diltiazem (active). |
| Excretion | Renal: 2-4% unchanged; hepatic metabolism with biliary excretion; fecal elimination accounts for ~10% |
| Half-life | 3-4.5 hours; prolonged in hepatic impairment (up to 10 hours) and in elderly |
| Protein binding | 70-80% bound to albumin |
| Volume of Distribution | 5-8 L/kg; indicates extensive tissue binding |
| Bioavailability | Oral: ~40-50% due to first-pass metabolism; IV: 100% |
| Onset of Action | IV: 1-2 minutes; oral: 30-60 minutes |
| Duration of Action | IV: 1-4 hours (rate-dependent); oral SR: 12-24 hours |
| Molecular Weight | 450.98 |
Intravenous continuous infusion: 5-15 mg/hour (0.25-0.33 mg/kg per hour).
| Dosage form | SOLUTION |
| Renal impairment | No adjustment required for GFR >10 mL/min; for GFR <10 mL/min, use with caution and monitor heart rate. |
| Liver impairment | Child-Pugh Class A: reduce dose to 5-10 mg/hour; Child-Pugh Class B: reduce to 2.5-5 mg/hour; Child-Pugh Class C: avoid use. |
| Pediatric use | Children: 0.25-0.33 mg/kg/hour continuous IV infusion; maximum 15 mg/hour. |
| Geriatric use | Elderly: initial dose at lower end of range (5-10 mg/hour); titrate slowly due to increased sensitivity and risk of bradycardia. |
| 1st trimester | Insufficient human data; animal studies show teratogenic effects at high doses; avoid unless clearly needed. |
| 2nd trimester | May cause fetal hypoxia and bradycardia; use only if benefit outweighs risk. |
| 3rd trimester | May cause uterine relaxation and delay labor; avoid near delivery due to risk of neonatal hypotension and bradycardia. |
Clinical note
No significant drug interactions Can cause hypernatremia and fluid overload.
| FDA category | Animal |
| Placental transfer | Diltiazem crosses the placenta; umbilical cord plasma levels are approximately 30-45% of maternal plasma levels. |
| Breastfeeding | Diltiazem is excreted into breast milk in low concentrations (milk-to-plasma ratio ~0.9). No adverse effects reported in infants, but monitor for bradycardia and hypotension. Consider alternative medications for long-term therapy. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | No adequate studies in pregnant women. In animal studies, diltiazem has been associated with embryofetal toxicity (skeletal abnormalities, increased mortality) at doses >5 times the maximum recommended human dose. Use only if potential benefit justifies risk. First trimester: potential teratogen, avoid unless essential. Second and third trimesters: may cause uterine hypoperfusion and fetal hypoxia due to maternal hypotension; monitor fetal heart rate and uterine activity if used near term. |
| Fetal Monitoring | Monitor maternal blood pressure, heart rate, and ECG periodically. Assess for signs of heart block or hypotension. For fetal well-being: ultrasound to monitor growth and amniotic fluid volume; nonstress test and biophysical profile if used in second or third trimester. If used during labor, monitor uterine activity and fetal heart rate continuously. |
| Fertility Effects | No specific human studies on fertility; animal studies (rats) showed no impairment of fertility at doses up to 10 times the MRHD. However, calcium channel blockers may affect sperm function in vitro; relevance unclear. Overall, unlikely to cause significant fertility impairment in humans. |
■ FDA Black Box Warning
There is no FDA black box warning for diltiazem.
| Common Effects | fluid replacement |
| Serious Effects |
Sick sinus syndrome (unless pacemaker)Second- or third-degree AV block (unless pacemaker)Severe hypotension (systolic <90 mmHg)Acute myocardial infarction with pulmonary congestionAtrial fibrillation/flutter with pre-excitation (e.g., Wolff-Parkinson-White syndrome)Known hypersensitivity to diltiazem
| Precautions | May cause bradycardia and AV block, Concomitant use with beta-blockers increases risk of bradycardia/heart failure, Avoid in patients with left ventricular dysfunction, May worsen heart failure in patients with reduced ejection fraction, Hepatic impairment requires dose adjustment, Monitor renal function in elderly; may cause hypotension, Avoid abrupt withdrawal |
| Food/Dietary | Avoid consumption of grapefruit and grapefruit juice as they inhibit CYP3A4 metabolism, increasing diltiazem serum concentrations and risk of toxicity. No other significant food interactions. |
| Clinical Pearls | Diltiazem hydrochloride in 0.72% sodium chloride is an intravenous calcium channel blocker used for rate control in atrial fibrillation/flutter and hypertension. Monitor heart rate and blood pressure closely; may cause bradycardia, hypotension, and heart block. Avoid in patients with sick sinus syndrome or second/third-degree AV block without a pacemaker. The 0.72% sodium chloride concentration provides isotonicity; ensure proper IV access to prevent extravasation tissue necrosis. Contraindicated with concurrent beta-blocker use due to additive bradycardic effects. |
| Patient Advice | This medication is given intravenously to control heart rate or lower blood pressure. · You will have your heart rate and blood pressure monitored continuously during infusion. · Report symptoms of dizziness, fainting, slow heart rate, or difficulty breathing. · Avoid grapefruit juice as it may increase drug levels and side effects. · Do not stop taking other heart medications without consulting your doctor. |
Loading safety data…