Lansoprazole Suspension (Various Strengths)

Route: Oral suspension. Shake well before each use. Administer by oral syringe or via nasogastric/gastrostomy tube as directed by the prescriber. When administered via NG or G-tube, flush the tube with water after administration to ensure complete delivery. The 8.4% sodium bicarbonate vehicle used in standard simplified lansoprazole suspension (SLS) maintains an alkaline pH to protect the acid-labile drug prior to reaching the stomach.

All dosing is prescriber-determined. Standard compounded concentrations used clinically include:

• Neonates/infants: prescriber-specified mg/kg/day dosing (typically 1–2 mg/kg/day), often divided.
• Children: dosing typically based on weight (commonly 15–30 mg/day for children >30 kg) as directed by the prescribing clinician.
• All doses and frequencies are determined by the prescribing clinician based on patient age, weight, and indication.
• Lansoprazole suspension is most effective when administered 30–60 minutes before meals.

Lansoprazole is a substituted benzimidazole that is a prodrug. After absorption and distribution to the parietal cell canaliculus (an acidic compartment), lansoprazole is protonated and converted to a sulfenamide (active form), which covalently and irreversibly binds to cysteine residues (Cys813 and Cys892) of the alpha-subunit of the gastric H⁺/K⁺-ATPase (proton pump). This inactivates the pump and suppresses gastric acid secretion for the life of the enzyme (approximately 24 hours), regardless of the stimulus (histamine, gastrin, or acetylcholine). Acid suppression is therefore sustained until new proton pump protein is synthesized. Lansoprazole also has some antibacterial activity against Helicobacter pylori (used in triple therapy).

Compounded lansoprazole oral suspension is primarily indicated for infants, children, and tube-fed patients with gastroesophageal reflux disease (GERD), erosive esophagitis, stress ulcer prophylaxis, or H. pylori eradication who cannot swallow intact capsules or tablets. This formulation is particularly well established in pediatric hospitals.

Monitoring: Symptom response (reduction in GERD symptoms, esophageal healing); complete blood count with prolonged use (PPIs may cause hypomagnesemia, vitamin B12 deficiency with long-term use); serum magnesium and vitamin B12 levels in patients on prolonged therapy; C. difficile-associated diarrhea (PPI use increases risk); bone density with very long-term use in children. Prescribers should document clinical indication and reassess periodically.

Contraindications:

• Known hypersensitivity to lansoprazole or any substituted benzimidazole PPI.
• Concurrent rilpivirine-containing antiretroviral regimens (PPIs substantially reduce rilpivirine plasma levels).

Warnings & Precautions:

• Stability: the compounded suspension has a short beyond-use date — typically 7 days refrigerated (in plastic syringes) per stability studies. Prescribers and patients must be counseled to discard unused suspension after the beyond-use date.
• Long-term PPI use: risk of Clostridioides difficile-associated diarrhea, hypomagnesemia, vitamin B12 deficiency, and possible reduction in bone mineral density with prolonged use.
• PPIs may mask symptoms of gastric malignancy.

Drug Interactions:

• Rilpivirine: contraindicated (substantially reduces rilpivirine absorption).
• Methotrexate: PPIs may increase methotrexate levels — monitor carefully.
• Clopidogrel: PPIs (particularly omeprazole) reduce active metabolite of clopidogrel via CYP2C19; lansoprazole has lower interaction potential but consider monitoring.
• Atazanavir, nelfinavir: reduced absorption with PPI; concurrent use not recommended.
• Drugs requiring acidic pH for absorption (itraconazole, ketoconazole, iron salts): reduced absorption.

Common Side Effects: Diarrhea, nausea, abdominal pain, headache; with long-term use: hypomagnesemia (muscle cramps, arrhythmias), vitamin B12 deficiency.

Compounded lansoprazole suspension must be stored under refrigeration (2°C–8°C) and protected from light (in amber-colored syringes or opaque containers). Stability studies indicate a beyond-use date of 7 days refrigerated (in plastic oral syringes) or up to 48 hours at room temperature. Shake well before each dose. Do not freeze. Dispense and store in amber-colored oral syringes as specified by Genesis Compounding. Use within the beyond-use date provided on the label.

Why is lansoprazole compounded as a suspension?

Commercial lansoprazole is available as intact or disintegrating capsules. Infants, young children, and patients dependent on feeding tubes cannot swallow capsules. Compounding into an oral suspension allows accurate weight-based dosing and administration via NG/G-tube in these populations.

How long does the compounded suspension remain stable?

Stability studies indicate compounded lansoprazole suspension in a sodium bicarbonate vehicle remains stable for approximately 7 days under refrigeration (in plastic oral syringes). Discard unused suspension after the beyond-use date on the label.

Should this be given with food?

Lansoprazole suspension is most effective when administered 30–60 minutes before a meal, as the proton pump must be actively secreting acid (post-prandial state) for the prodrug to be converted and bind the pump effectively.

Is this FDA-approved?

No. This is a patient-specific, prescriber-directed 503A compounded preparation from Genesis Compounding, not FDA-approved as a compounded drug. The commercial oral capsule formulation is FDA-approved, but the compounded suspension is prepared to meet a specific patient need.

What are signs of serious side effects?

Prolonged PPI use can cause hypomagnesemia (symptoms: muscle cramps, irregular heartbeat, seizures) and C. difficile-associated diarrhea (watery or bloody diarrhea, abdominal cramping). Report these symptoms promptly to the prescriber.