Olmezest Tablet: An Angiotensin-II Receptor Blocker (ARB) for Hypertension

Olmezest tablet contains Olmesartan medoxomil, an angiotensin-II receptor blocker (ARB). It is indicated for the treatment of hypertension (high blood pressure) and can be used alone or in combination with other antihypertensive agents.

How Olmezest Works (Pharmacology)

Olmesartan acts by selectively blocking the binding of angiotensin II to the AT1 receptor in vascular smooth muscle. Angiotensin II is a powerful vasoconstrictor (narrows blood vessels) and a key component of the renin-angiotensin system, which plays a major role in regulating blood pressure.

By blocking the AT1 receptor, Olmesartan prevents angiotensin II from:

• Causing vasoconstriction.
• Stimulating the synthesis and release of aldosterone (a hormone that increases sodium and water retention).
• Stimulating the heart.
• Promoting renal reabsorption of sodium.

Unlike ACE inhibitors, Olmesartan medoxomil does not inhibit ACE (Kininase II) and therefore does not affect the response to bradykinin (a substance that can cause cough). Although blocking the angiotensin II receptor inhibits the negative feedback on renin secretion (leading to increased plasma renin activity and circulating angiotensin II levels), these increases do not overcome Olmesartan's blood pressure-lowering effect. Olmesartan has a significantly higher affinity (more than 12,500-fold greater) for the AT1 receptor than for the AT2 receptor, ensuring its selective action in cardiovascular homeostasis.

Key Indications & Benefits

Olmezest tablet is indicated for:

• Treatment of hypertension (high blood pressure).
• Can be used as monotherapy or in combination with other antihypertensive agents.

Dosage & Administration

Dosage must be individualized, and Olmezest may be administered with or without food. Always consult a registered physician for medication use.

• Usual recommended starting dose (monotherapy, not volume-contracted patients): 20 mg once daily.
• For further blood pressure reduction (after 2 weeks of therapy): The dose may be increased to 40 mg once daily.
• Maximum effect: Doses above 40 mg do not appear to offer a greater effect.
• Frequency: Twice-daily dosing offers no advantage over the same total dose given once daily.

Special Populations:

• Elderly patients: No initial dosage adjustment is recommended.
• Patients with moderate to marked renal impairment (creatinine clearance <40 ml/min): No initial dosage adjustment is recommended.
• Patients with moderate to marked hepatic dysfunction: No initial dosage adjustment is recommended.
• Patients with possible depletion of intravascular volume (e.g., those on diuretics, especially with impaired renal function): Olmesartan should be initiated under close medical supervision, and consideration should be given to using a lower starting dose.
• Pediatric use: Safety and effectiveness in pediatric patients have not been established.

Important Considerations & Warnings

It is crucial to discuss your full medical history with your doctor before taking Olmezest.

Contraindications:

• Patients who are hypersensitive to any component of this product.
• Pregnancy (especially during the second and third trimesters).

Side Effects:

Olmezest is generally well-tolerated, with an incidence of adverse reactions similar to placebo in clinical trials involving over 3825 patients.

• Most common (occurred in more than 1% of patients treated with Olmezest and at a higher incidence vs. placebo):
  • Dizziness (3% in Olmezest group vs. 1% in placebo group).
• Other adverse reactions (occurred in >1% of Olmezest patients but at similar or greater incidence in placebo group):
  • Back pain, bronchitis, increased creatine phosphokinase, diarrhea, headache, hematuria, hyperglycemia, hypertriglyceridemia, influenza-like symptoms, pharyngitis, rhinitis, and sinusitis.
• Cough: Incidence was similar in placebo (0.7%) and Olmezest (0.9%) patients, indicating a low likelihood of cough compared to ACE inhibitors.
• Withdrawals due to adverse reactions: 2.4% for Olmezest vs. 2.7% for control patients.
• No significant differences in adverse reactions based on gender, age, or racial groups were observed between Olmezest and placebo-treated patients in the trials.

Pregnancy & Lactation:

• Pregnancy:Discontinue this product as soon as possible if pregnancy is detected. Drugs that act directly on the renin-angiotensin system (like Olmesartan) can cause injury and even death to the developing fetus when used during the second and third trimesters.
• Lactation: It is not known whether Olmesartan is excreted in human milk, though it is secreted at low concentrations in the milk of lactating rats. Due to the potential for adverse effects on the nursing infant, a decision should be made whether to discontinue nursing or discontinue the drug, considering its importance to the mother.

Precautions & Warnings:

• Renal Function: As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function may be anticipated in susceptible individuals. In patients whose renal function depends on this system (e.g., patients with severe congestive heart failure), ARBs have been associated with oliguria (reduced urine output) and/or progressive azotemia (high nitrogen waste products in blood) and (rarely) acute renal failure and/or death. Similar results may be anticipated with Olmezest.
• Intravascular Volume Depletion: For patients with possible depletion of intravascular volume (e.g., those on diuretic therapy, especially with impaired renal function), Olmesartan should be initiated under close medical supervision with a lower starting dose considered.

Drug Interactions:

• Digoxin or Warfarin: No significant drug interactions reported.
• Antacids: Bioavailability of olmesartan was not significantly altered.
• Cytochrome P450 System: Olmezest is not metabolized by the cytochrome P450 system and does not affect P450 enzymes; thus, interactions with drugs that inhibit, induce, or are metabolized by these enzymes are not expected.
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), including selective COX-2 Inhibitors:
  • In elderly, volume-depleted patients (including those on diuretic therapy), or those with compromised renal function, co-administration of NSAIDs (including COX-2 inhibitors) with ARBs (like Olmezest) may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible.Monitor renal function periodically in patients receiving both Olmezest and NSAID therapy.
  • The antihypertensive effect of ARBs may be attenuated (reduced) by NSAIDs, including selective COX-2 inhibitors.

Overdose Effects:

• There is no specific experience of overdose with Olmezest.
• Most likely effects: Hypotension (low blood pressure) and tachycardia (fast heart rate); bradycardia (slow heart rate) could occur if parasympathetic (vagal) stimulation is present.
• Management:
  • If intake is recent,gastric lavage (stomach pumping) or induction of emesis (vomiting) may be considered.
  • Clinically significant hypotension requires active support of the cardiovascular system, including close monitoring of heart and lung function, elevation of the extremities, and attention to circulating fluid volume and urine output.

Storage Conditions

Store in a cool & dry place below 30°C, protect from light & moisture. Keep out of the reach of children.