Visco

Description

Contraindications

• Hypersensitivity to any of the ingredients.

Precautions

• Use with caution in patients with chronic renal impairment, congestive heart failure (CHF), edema, cirrhosis, and those on low sodium diets.
• Caution is advised in patients with recent gastrointestinal hemorrhage.
• To minimize drug interactions, administer Visco Liquid 2-3 hours before or after other medications.
• Pregnancy and Lactation: Use with caution. Excretion in breast milk is unknown.

Interactions

• Aluminium Hydroxide:
  • Enhanced absorption with citrates or ascorbic acid.
  • Decreases absorption of: allopurinol, tetracyclines, quinolones, cephalosporins, biphosphonate derivatives, corticosteroids, cyclosporin, delavirdine, iron salts, imidazole antifungals, isoniazid, mycophenolate, penicillamine, phosphate supplements, phenytoin, phenothiazines, trientine.
• Magnesium Hydroxide:
  • Decreases absorption of tetracyclines and biphosphonates. Separate administration of these and other drugs by approximately 2 hours.
• Simethicone, Sodium Alginate:
  • No well-documented interactions.

Possible Side Effects

Gastrointestinal:

• Most frequently reported side effects include constipation (due to aluminum hydroxide) and diarrhea (due to magnesium hydroxide).

Systemic Effects (especially with long-term use or in specific patient populations):

• Aluminum toxicity: Patients with renal failure are at risk due to aluminum hydroxide ingestion and exposure from dialysate solutions. Can lead to bone, joint, and brain deposition.
  • Concurrent administration with citrate-containing products can lead to unusually high serum aluminum concentrations and severe toxicity, especially in renal failure.
• Hypermagnesemia: Signs and symptoms may include hypotension, nausea, vomiting, EKG changes, respiratory depression, loss of deep tendon reflex, dilated pupils, altered mental status, and coma.
• Hypophosphatemia: With long-term aluminum hydroxide use, especially with poor diets, this can lead to muscle weakness, rhabdomyolysis, hemolysis, and encephalopathy.
• Osteomalacia: Can occur due to hypophosphatemia or aluminum accumulation in bone, particularly in chronic renal failure patients, leading to malaise, bone pain, muscular weakness, and fractures.
• Encephalopathy (due to aluminum accumulation): Characterized by speech disorders, dysarthria, dyspraxia, dysphasia, tremor, myoclonus, seizures, coma, and ultimately death. EEG changes may be observed.
• Renal: Rarely, formation of renal calculi (kidney stones) due to hypercalciuria with aluminum hydroxide use.

Mechanism of Action

• Aluminum Hydroxide: Neutralizes stomach hydrochloric acid to form aluminum chloride salt plus water, thereby increasing gastric pH.
• Magnesium Hydroxide: Acts as an osmotic laxative, retaining fluid in the bowel and distending the colon, which increases peristaltic activity. It also reacts with hydrochloric acid to form magnesium chloride.
• Simethicone: Reduces the surface tension of gas bubbles, causing them to disperse and preventing gas pockets in the GI system.
• Alginic acid (Sodium Alginate): When combined with an antacid or H2-antagonist, it reacts with gastric acid to form a viscous gel that acts as a mechanical barrier, reducing gastro-oesophageal reflux.