Generic Calan

Introduction

Calan is a prescription medication whose active ingredient is verapamil, a calcium‑channel blocker belonging to the blood‑pressure drug group. In the United Kingdom, Calan is prescribed mainly for the management of hypertension, angina pectoris, and certain cardiac rhythm disorders. Verapamil’s ability to relax vascular smooth muscle and slow electrical conduction through the heart makes it a versatile option for cardiovascular control. The formulation is marketed in tablet form and is manufactured by several licensed pharmaceutical companies under the Calan trade name.

What is Calan?

Calan contains the single active compound verapamil hydrochloride. It is classified as a non‑dihydropyridine calcium‑channel antagonist. The drug was first introduced in the early 198s and has since become a standard therapy for several heart‑related conditions. In the UK, Calan tablets are produced by manufacturers that hold a marketing authorisation from the Medicines and Healthcare products Regulatory Agency (MHRA). The product is available in several strengths, allowing clinicians to tailor dosing to the individual patient’s needs.

How Calan Works

Verapamil blocks L‑type calcium channels located in vascular smooth muscle, the myocardium, and the sino‑atrial and atrioventricular nodes. By inhibiting calcium influx, the drug produces three principal effects:- Vasodilation – arterial smooth muscle relaxes, leading to reduced peripheral resistance and lower systolic and diastolic blood pressure.

• Negative inotropy – the contractile force of the heart muscle diminishes, decreasing myocardial oxygen demand, which is helpful in angina.
• Negative dromotropic effect – conduction velocity through the atrioventricular node slows, stabilising abnormal rapid heart rhythms such as supraventricular tachycardia.

On oral administration, verapamil reaches peak plasma concentrations within 1–2 hours, with a half‑life of approximately 3–7 hours for the immediate‑release formulation and up to 12 hours for extended‑release tablets. The drug is metabolised primarily by hepatic CYP3A4 enzymes and excreted in urine and bile.

Conditions Treated with Calan

• Essential hypertension – High blood pressure affects an estimated 13 % of adults in the UK. Verapamil lowers systemic vascular resistance, contributing to long‑term blood‑pressure control when used alone or in combination with other antihypertensive agents.
• Stable angina pectoris – By decreasing myocardial oxygen consumption, verapamil relieves chest pain during exertion and improves exercise tolerance.
• Supraventricular tachycardia (SVT) – The drug’s AV‑node blocking properties make it effective for terminating episodes of paroxysmal SVT and for rate control in atrial fibrillation.
• Hypertrophic cardiomyopathy (off‑label) – Small studies have shown that verapamil may improve diastolic filling and reduce outflow‑tract gradients, though this use remains specialist‑driven.

These indications are supported by the National Institute for Health and Care Excellence (NICE) guidelines and the British National Formulary (BNF).

Who is Calan For?

• Adults with newly diagnosed or uncontrolled hypertension who require additional blood‑pressure reduction beyond lifestyle measures.
• Patients with chronic stable angina whose symptoms persist despite first‑line beta‑blockers or nitrates.
• Individuals experiencing recurrent SVT where catheter ablation is not immediately feasible.
• Older adults who may benefit from the once‑daily extended‑release formulation, provided renal and hepatic function are within acceptable limits.

Calan is not recommended for patients with severe heart failure (NYHA class III–IV), advanced atrioventricular block without a pacemaker, or known hypersensitivity to verapamil or other calcium‑channel blockers. Caution is also advised in patients with severe hepatic impairment, uncontrolled asthma, or concomitant use of strong CYP3A4 inhibitors (e.g., clarithromycin, ketoconazole).

Risks, Side Effects, and Interactions

Common

• Headache
• Flushing or warmth in the face
• Peripheral edema (especially ankle swelling)
• Constipation
• Dizziness, particularly on standing (orthostatic hypotension)

Rare

• Bradycardia (heart rate < 50 bpm)
• PR‑interval prolongation on ECG
• Gingival hyperplasia (overgrowth of gum tissue)
• Visual disturbances (blurred vision)

Serious

• Severe hypotension leading to syncope
• Life‑threatening cardiac arrhythmias, particularly when combined with digoxin or beta‑blockers
• Acute hepatic failure (very rare)
• Allergic reactions such as Stevens‑Johnson syndrome

Drug–drug interactions that merit clinical attention include:

• Beta‑blockers – additive negative chronotropic effect may cause profound bradycardia.
• Digoxin – verapamil raises digoxin plasma concentrations; monitor levels and adjust dosage.
• CYP3A4 inhibitors (e.g., erythromycin, ritonavir) – increase verapamil exposure, raising the risk of toxicity.
• CYP3A4 inducers (e.g., rifampicin, carbamazepine) – reduce therapeutic effect, possibly requiring dose escalation.
• Grapefruit juice – inhibits intestinal CYP3A4, augmenting verapamil levels.

Patients should always disclose over‑the‑counter medicines, herbal supplements, and dietary habits to their prescriber.

Practical Use: Dosing, Missed Dose, Overdose

• Standard dosing – For hypertension, the usual starting dose of immediate‑release tablets is 80 mg three times daily; the extended‑release form starts at 240 mg once daily. Angina dosing typically begins at 120 mg three times daily, with titration based on symptom control.
• Missed dose – If a dose is forgotten and it is less than 12 hours until the next scheduled tablet, take the missed dose as soon as remembered. If it is longer than 12 hours, skip the forgotten dose and resume the regular schedule; do not double‑dose.
• Overdose – Symptoms may include severe hypotension, bradycardia, cardiac conduction delays, and respiratory depression. Immediate medical attention is required. Activated charcoal may be considered if ingestion occurred within one hour. Supportive care, intravenous fluids, and atropine for bradyarrhythmias are standard interventions.

Precautions – Take Calan with food to minimise gastrointestinal upset. Alcohol can potentiate hypotensive effects and should be limited. Patients with renal impairment may need dose adjustment, especially when using the immediate‑release formulation.

Buying Calan from Our Online Pharmacy

Calan can be obtained safely from our online pharmacy in the UK. Our service offers several advantages for patients seeking reliable access to this essential cardiovascular medicine:

• Affordable pricing – We source generic verapamil at near‑manufacturer cost, passing the savings directly to you.
• Verified quality – All batches are supplied by MHRA‑approved overseas licensed pharmacies, guaranteeing authenticity and compliance with UK standards.
• Guaranteed delivery – Discreet packaging is shipped via express courier (typically 3–7 working days) or regular airmail (approximately 2–3 weeks), with full tracking available.
• Online‑only convenience – Our pharmacy broker model connects you with reputable international suppliers, allowing seamless ordering without the need for a local pharmacy visit.

We operate as a pharmacy‑broker service, respecting patient privacy while ensuring that every shipment meets stringent safety and regulatory requirements.

FAQ

• Can Calan be taken with other antihypertensive drugs?
  Yes, verapamil is often combined with ACE inhibitors, diuretics, or thiazide‑type agents to achieve better blood‑pressure control. However, clinicians should monitor for additive hypotensive effects and adjust doses accordingly.

• Is there a difference between immediate‑release and extended‑release Calan tablets?
  Immediate‑release tablets are taken two to three times daily and reach peak concentrations quickly, while extended‑release tablets are designed for once‑daily dosing with a smoother plasma‑level curve. The choice depends on the therapeutic goal and patient convenience.

• What should I do if I experience severe dizziness after a dose?
  Sit or lie down immediately to prevent falls and contact your healthcare provider. Persistent or worsening dizziness may indicate excessive blood‑pressure reduction and may require dose adjustment.

• Does Calan interact with over‑the‑counter pain relievers such as ibuprofen?
  Non‑steroidal anti‑inflammatory drugs (NSAIDs) can blunt the antihypertensive effect of verapamil by promoting sodium retention. Short‑term occasional use is generally safe, but regular NSAID consumption should be discussed with a clinician.

• **Is it safe to travel internationally with Calan tablets?
  Yes, provided you carry the medication in its original labelled container, accompanied by a copy of the prescription or a doctor’s letter if required. Keep tablets in your carry‑on luggage to avoid temperature extremes in the cargo hold.

• How should Calan be stored in different climates?
  Store tablets at a controlled room temperature of 20–25 °C (68–77 °F). In very hot or humid environments, keep the medication in a sealed container with a desiccant packet, away from direct sunlight, to maintain potency.

• Are there known differences in formulation between UK and overseas versions?
  The active ingredient (verapamil hydrochloride) is identical across regions, but inactive excipients such as fillers or dyes may vary. Patients with known excipient allergies should review the specific product information sheet supplied by the manufacturer.

• Can Calan affect drug testing for employment or sport?
  Verapamil is not a prohibited substance under standard occupational drug‑screening panels or World Anti‑Doping Agency (WADA) rules. Routine testing will not flag therapeutic doses of verapamil.

• What is the historical significance of verapamil in cardiology?
  Introduced in the 197s, verapamil was the first non‑dihydropyridine calcium‑channel blocker to demonstrate efficacy in both hypertension and cardiac arrhythmia management. Large multicenter trials in the 198s established its role as a cornerstone therapy for several cardiovascular conditions.

• Does Calan have any effect on blood glucose levels?
  Verapamil has been investigated for modest glucose‑lowering properties in early‑phase studies on type 2 diabetes, but the effect is not clinically significant for routine diabetes management. Patients with diabetes should continue their standard antidiabetic regimen while on Calan.

• Why might constipation be more common with Calan than with other blood‑pressure drugs?
  Calcium‑channel blockers reduce smooth‑muscle contractility throughout the gastrointestinal tract, leading to slowed intestinal transit. Adequate dietary fibre, fluid intake, and regular physical activity can ameliorate this side effect.

Glossary

Calcium‑channel blocker

A class of medication that inhibits the influx of calcium ions into cardiac and vascular smooth‑muscle cells, causing relaxation of blood vessels and reduction of heart‑rate conduction.

Negative dromotropic effect

The slowing of electrical conduction velocity through the heart’s atrioventricular node, which can be therapeutic in certain tachyarrhythmias.

CYP3A4

An enzyme in the liver and intestinal wall responsible for metabolising many drugs; inhibitors or inducers of CYP3A4 can markedly alter verapamil plasma levels.

Orthostatic hypotension

A drop in blood pressure that occurs when standing up quickly, potentially causing dizziness or fainting.

⚠️ Disclaimer

The information provided about Calan is for general knowledge only. It does not replace professional medical consultation. All treatment decisions should be made under the supervision of a qualified healthcare provider. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to Calan 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.