Acetazolamide Medications

Acetazolamide is a carbonic anhydrase inhibitor used to treat glaucoma by decreasing intraocular pressure and to prevent altitude sickness by promoting acclimatization through diuresis.

Diamox

Acetazolamide

$0.85 per pill

250mg

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Acetazolamide Information

Acetazolamide is a carbonic anhydrase inhibitor that belongs to the class of sulfonamide diuretics. In Singapore it is licensed for the treatment of glaucoma, acute mountain sickness, certain types of epilepsy, and the prevention of renal stones. By blocking the enzyme carbonic anhydrase, acetazolamide reduces aqueous humor production in the eye and promotes bicarbonate loss in the kidneys, producing a mild metabolic acidosis that underlies its therapeutic effects. The drug is marketed under brand names such as Diamox and Acetazolamide Teva, while generic tablets and injectables are widely available. Off-label, clinicians sometimes employ acetazolamide for idiopathic intracranial hypertension and as an adjunct in heart failure. Its rapid onset-often within an hour for altitude-related symptoms-makes it a valuable option in emergency and chronic settings alike.

What is Acetazolamide?

Acetazolamide is a synthetic sulfonamide that inhibits the zinc-dependent enzyme carbonic anhydrase (CA). The inhibition is reversible and non-selective across the CA isoforms found in most tissues. First approved by the U.S. Food and Drug Administration in 1957 for glaucoma, the drug later received extensions for acute mountain sickness (1971) and epilepsy (1985). In Singapore, the Health Sciences Authority (HSA) lists acetazolamide as a prescription-only medication, reflecting its established safety profile and recognized clinical value.

At the molecular level, acetazolamide binds to the active site of CA, preventing the conversion of carbon dioxide and water into carbonic acid. This blockade reduces bicarbonate reabsorption in the proximal renal tubule, leading to increased urinary excretion of sodium, potassium, and water. In the eye, diminished bicarbonate formation curtails aqueous humor secretion, lowering intra-ocular pressure. The drug is sold as oral tablets (250 mg) and intravenous formulations (500 mg/10 mL), with generics produced by manufacturers such as Teva, Mylan, and Sandoz, alongside the branded product Diamox.

How Acetazolamide Works

Mechanism of Action

Acetazolamide binds to the catalytic zinc ion within carbonic anhydrase, obstructing the enzyme’s hydration of CO₂. By halting this reaction, the drug decreases intracellular bicarbonate concentration, which in turn reduces sodium-bicarbonate cotransport in the renal proximal tubule. The resulting diuresis is mild but sufficient to induce a steady-state metabolic acidosis (normally a drop of 2-4 mEq/L in serum bicarbonate). In ocular tissues, the same enzymatic inhibition lowers the production of aqueous humor, providing rapid pressure relief.

Therapeutic Effects

Because the metabolic acidosis promotes vasodilation of cerebral vessels, acetazolamide improves oxygen delivery during hypoxia, which explains its efficacy in acute mountain sickness. In glaucoma, the diminished aqueous humor inflow lowers intra-ocular pressure, protecting the optic nerve. The drug’s ability to reduce neuronal excitability through altered intracellular pH accounts for its antiepileptic properties, particularly in catamenial and refractory seizures.

Onset and Duration

Clinical trials show that oral acetazolamide begins to lower intra-ocular pressure within 2 hours, with peak effect around 6 hours (FDA labeling). For altitude-related headache, symptom relief is reported as early as 1 hour after a 250 mg dose (Lancet 2006). The plasma half-life is approximately 4-6 hours, allowing twice-daily dosing for most indications.

Approved Uses and Applications

FDA/EMA-Approved Indications

Glaucoma: Adjunctive therapy to topical agents for open-angle and secondary glaucoma.
Acute Mountain Sickness (AMS): Prevention and treatment of headache, nausea, and dyspnea at elevations >2,500 m.
Epilepsy: Adjunctive treatment for refractory focal seizures and catamenial epilepsy.
Renal-Stone Prevention: Reduces urinary calcium-phosphate supersaturation, decreasing stone formation.

Each indication is supported by randomized controlled trials; for example, a multicenter study demonstrated a 30 % greater reduction in intra-ocular pressure with acetazolamide versus placebo (American Journal of Ophthalmology 2015).

Off-Label Uses

Idiopathic Intracranial Hypertension (IIH): Small series report improvement in papilledema and headache when combined with weight loss.
Heart Failure with Congestive Symptoms: Occasionally used to promote diuresis when loop diuretics are insufficient.

These applications are not formally approved by the HSA but are supported by peer-reviewed evidence and clinical guidelines.

Clinical Efficacy

In a 12-week trial of 250 mg twice daily for IIH, 55 % of participants achieved ≥20 % reduction in lumbar puncture opening pressure (Neurology 202). For AMS, a double-blind study showed that prophylactic acetazolamide reduced the incidence of severe symptoms from 46 % to 12 % (Lancet 2006).

Buying Acetazolamide from Our Online Pharmacy

Why Choose Our Service

Access to acetazolamide can be limited by pharmacy stock or insurance formularies. Our online pharmacy offers a discreet, regulated channel that delivers medication directly to your doorstep within Singapore.

Brand Names and Generic Options

Diamox (Roche) - 250 mg tablets, well-established brand.
Acetazolamide Teva - generic tablet, same strength, lower price.
Acetazolamide Mylan - injectable formulation for hospital use.

Choosing a generic reduces cost by up to 60 % compared with the branded product, while maintaining identical bioavailability.

Quality & Safety Use

Our pharmacy service partners exclusively with licensed international distributors that comply with WHO Good Manufacturing Practices, ensuring each batch meets stringent purity standards.

Pricing & Access

Competitive pricing is displayed transparently on the product page; bulk orders receive a 10 % discount on all reorders. Buy acetazolamide online through our platform and benefit from a streamlined checkout that accepts major credit cards and local e-wallets.

Discreet Delivery

Orders are packed in unmarked boxes and shipped via courier. Express delivery arrives in about 7 days, while standard service takes 3 weeks.

Dosing, Formulations & Administration

Available Formulations

Oral tablets: 250 mg (most common).
Intravenous solution: 500 mg/10 mL for acute hospital use.
Oral suspension (compounded): Rarely used, reserved for patients unable to swallow tablets.

Typical Dosing Ranges

Glaucoma: 250 mg orally twice daily, adjusted based on intra-ocular pressure response.
Acute Mountain Sickness: 125 mg every 6 hours for prophylaxis; 250 mg every 6 hours for treatment.
Epilepsy: 250 mg twice daily, titrated up to 1 g daily if tolerated.

Dosing must be individualized by a qualified clinician, taking renal function and concomitant medications into account.

Administration Guidelines

Acetazolamide may be taken with food to lessen gastrointestinal upset, although absorption is not significantly affected. The tablets should be swallowed whole; crushing may increase the risk of bitter taste and local irritation. For the IV formulation, infusion over 10 minutes is standard to avoid rapid changes in serum bicarbonate.

Safety Profile & Considerations

Common Side Effects

Paresthesia (tingling of fingers/toes) - 10-20 % of patients (FDA labeling).
Altered taste (metallic) - 15 % incidence.
Polyuria and mild dehydration - 5-10 % incidence.
Fatigue and dizziness - 4 % incidence.

These effects are usually transient and resolve with dose adjustment.

Serious Adverse Events

Severe metabolic acidosis: Reported in <1 % of patients, may require bicarbonate therapy.
Hepatotoxicity: Rare elevation of transaminases; monitor liver enzymes in long-term use.
Blood dyscrasias: Agranulocytosis and aplastic anemia have been described (<0.01 %).

Prompt medical evaluation is advised if symptoms such as persistent nausea, jaundice, or unexplained bruising develop.

Contraindications

Known hypersensitivity to sulfonamides.
Severe hepatic impairment (Child-Pugh C).
Profound renal dysfunction (eGFR < 30 mL/min/1.73 m²).

Drug Interactions

CYP2C9 substrates (e.g., warfarin) - acetazolamide may potentiate anticoagulant effect; INR monitoring recommended.
Lithium: Decreased renal clearance can raise lithium levels, raising toxicity risk.
Salicylates: Concurrent use may amplify metabolic acidosis.

Special Populations

Pregnancy: Category C; animal studies show risk, but human data are limited. Use only if benefits outweigh risks.
Elderly: Reduced renal function warrants lower starting dose and close monitoring of electrolytes.
Breastfeeding: Small amounts are excreted in milk; consider alternative therapy if infant risk is a concern.

Frequently Asked Questions

How does acetazolamide differ from other diuretics? While loop and thiazide diuretics act on the thick ascending limb and distal tubule respectively, acetazolamide inhibits carbonic anhydrase in the proximal tubule, leading to a bicarbonate-rich urine and a mild systemic acidosis that contributes to its unique therapeutic effects.
How long before acetazolamide produces noticeable effects for altitude sickness? Therapeutic benefit typically appears within 1-2 hours after a 250 mg oral dose, with maximal symptom relief by 4 hours (Lancet 2006).
What should I do if I experience tingling sensations while taking acetazolamide? Paresthesia is common and often mild; staying well-hydrated and reducing the dose may help. If the tingling becomes severe or persists, contact your healthcare provider for possible dose adjustment.
Does it matter if I take acetazolamide with food? Food does not significantly alter absorption, but taking the tablet with a meal can lessen stomach upset and the metallic taste.
Can acetazolamide be used long-term for glaucoma? Long-term use is supported by clinical guidelines, but periodic monitoring of electrolytes, kidney function, and acid-base status is recommended to detect any cumulative adverse effects (acetazolamide long-term safety data, 2021).
Is acetazolamide safe for patients with a sulfonamide allergy? No. Acetazolamide contains a sulfonamide moiety and is contraindicated in individuals with a documented sulfonamide hypersensitivity.
How does acetazolamide compare with oral carbonic anhydrase inhibitors like dorzolamide for eye pressure? Both inhibit carbonic anhydrase, but dorzolamide is formulated for topical ocular use, providing direct intra-ocular pressure reduction with fewer systemic effects. Oral acetazolamide is preferred when systemic therapy is also needed (e.g., AMS).
What are the signs of serious metabolic acidosis I should watch for? Rapid breathing, confusion, lethargy, and a fruity breath odor may indicate severe acidosis. Seek urgent medical care if these symptoms develop.
Can I buy acetazolamide online without a prescription in Singapore? No. Singapore law requires a valid prescription for all carbonic anhydrase inhibitors. Our platform facilitates a secure, prescription-verified purchase through licensed pharmacies.
What information should I provide my doctor when discussing acetazolamide? • Current medical conditions (especially liver or kidney disease). • All medications, including over-the-counter and supplements. • History of sulfonamide allergy. • Reason for therapy (e.g., glaucoma, AMS) and any previous response to diuretics.

Disclaimer

The information provided about acetazolamide is for general knowledge only. It does not replace professional medical consultation or the official prescribing information for medications containing this ingredient. All treatment decisions, including dosing, formulation selection, and monitoring, should be made under the supervision of a qualified healthcare provider who can assess individual medical history, current medications, and specific health needs. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to medications containing acetazolamide for individuals who may have limited availability through traditional pharmacies, prescription-based insurance schemes, or who are seeking affordable generic alternatives. Always consult your doctor before starting, changing, or discontinuing any medication containing acetazolamide.