Zopranol

Quick links to important sections

Zopranol

Selected form

Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Zopranol

What is Zopranol?

Zopranol is a pharmaceutical medication containing the active substance zofenopril calcium. It belongs to a class of drugs known as Angiotensin-Converting Enzyme (ACE) inhibitors. These medications primarily interact with the renin-angiotensin-aldosterone system, a hormonal mechanism in the body that regulates blood pressure and fluid balance.

Mechanism of Action

The active ingredient, zofenopril, is a prodrug. This means that after ingestion, it is converted by the liver into its active form, zofenoprilat. This active metabolite works by inhibiting the enzyme responsible for converting angiotensin I into angiotensin II.

Angiotensin II is a potent substance that causes blood vessels to constrict (narrow). By reducing the production of this substance, Zopranol facilitates:

  • Vasodilation: The relaxation and widening of blood vessels.
  • Reduced Peripheral Resistance: Lowering the pressure the heart must pump against.
  • Decreased Aldosterone Secretion: Assisting the body in managing salt and water levels.

Therapeutic Properties

Zopranol is characterized by its high lipophilicity (fat solubility), which allows the medication to penetrate various tissues effectively. Unlike some other ACE inhibitors, it contains a sulfhydryl group in its chemical structure. Research into this class of compounds suggests that this specific chemical makeup may contribute to antioxidant properties and a particular affinity for cardiac tissue.

In a clinical context, the medication is used to manage long-term cardiovascular conditions by reducing the workload on the heart and improving blood flow throughout the circulatory system. This makes it a foundational component in the management of high blood pressure and the protection of heart function following cardiac events.

Regulatory References

  1. EMA Source
  2. DrugBank Source

What side effects are possible with Zopranol?

Possible Side Effects and Safety Information

The safety profile for Zopranol (zofenopril calcium) is officially documented by regulatory agencies and classified according to the frequency and type of adverse reactions observed. The profile is segmented into System-Organ Classes (SOC) and categorized by commonality, ranging from common to very rare.

Adverse Reaction Frequency

Classification Examples of Documented Reactions
Common (1 in 10 to 1 in 100 people) Headache, Dizziness, Cough, Fatigue, Nausea, Vomiting
Uncommon (1 in 100 to 1 in 1,000 people) Angioedema, Hypotension, Mood changes, Insomnia, Dyspnoea
Rare (1 in 1,000 to 1 in 10,000 people) Pancreatitis, Paresthesia, Taste disturbance
Very Rare (Fewer than 1 in 10,000 people) Agranulocytosis, Hepatic dysfunction, Severe skin reactions

Serious Adverse Reactions and Constraints

Regulatory documents identify specific reactions that, though rare, are considered serious, including Angioedema (swelling of the face, throat, or tongue), severe drops in blood pressure (Hypotension), and severe Blood and Lymphatic System Disorders. These serious reactions often fall under the uncommon or very rare frequency tiers.

Official safety constraints note that Zopranol is contraindicated in pregnancy due to the potential for fetal harm and mortality, particularly during the second and third trimesters. An exaggerated hypotensive response is a documented pattern that may be observed following the initial dose or during dose escalation. Caution is also required in individuals with bilateral renal artery stenosis.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose with Zopranol (zofenopril calcium) is officially documented to present primarily with manifestations of profound hemodynamic instability, most commonly severe hypotension (low blood pressure), which may be accompanied by tachycardia or bradycardia. A severe consequence cited in regulatory labeling is the risk of reversible renal failure or damage to kidney function.

Certain manifestations are considered life-threatening and require immediate medical attention. These include the development of life-threatening angioedema (swelling of the throat or airway) and severe hypotension persisting below a systolic blood pressure of 90 mmHg. In case of suspected overdose or the onset of severe symptoms, individuals must seek immediate medical advice or contact emergency services. Regulatory guidance mandates that the medication be discontinued if severe hypotension is confirmed.

Management protocols state that no specific antidote is known for Zopranol overdose. Treatment is restricted to symptomatic and supportive measures. These measures include placing the individual in a supine position and administering intravenous fluids to correct circulatory instability. Patients with severe acute symptoms must be monitored closely, preferably in a hospital setting.

Therapeutic Uses of Zopranol

What Zopranol Treats: Main Uses and Benefits


The primary role of Zopranol therapy is to help manage chronic Elevated Blood Pressure Readings and to support heart health in patients with ischemic heart conditions. The medication's main therapeutic indications are for treating mild to moderate essential hypertension, and its use is relevant in the early phases of treatment for patients with acute myocardial infarction.

The application of this therapy is relevant across conditions presenting with systemic or localized discomfort related to vascular health.

Stabilization and Risk Management

Zopranol is relevant for use in the acute and recovery phases following a Myocardial Infarction (heart attack). This therapy is initiated to help achieve cardiovascular stabilization and supports heart health in the long term. For patients with Ischemic Heart Disorders or high cardiovascular risk profiles, the supportive therapeutic benefit may assist with easing the overall symptom burden related to heart disease.

“The goal is to provide support that helps ease the overall symptom burden and assists with maintaining functional stability during difficult episodes.”

By controlling pressure and reducing High Cardiac Workload, the medication contributes to easing strain on the vascular network and helps to reduce the risk of future vascular damage.

Quick Fact: Relief for Elevated Blood Pressure Readings
Primary Domain Cardiovascular Disease Management
Core Benefit Sustained Blood Pressure Control
Typical Context Chronic Essential Hypertension

Regulatory References

  1. HPRA Summary of Product Characteristics

Eligibility and Restrictions for Use

The eligibility for Zopranol (zofenopril calcium) is strictly defined by regulatory documents, specifying who may use the medicine and who is prohibited. Use is allowed for adults with essential hypertension and in the early phases of acute myocardial infarction.

Contraindications and Restrictions

Zopranol is contraindicated and must not be used in the following populations or conditions:

  • Patients with a known hypersensitivity to zofenopril calcium or any other Angiotensin-Converting Enzyme (ACE) Inhibitor.
  • Patients with a history of angioneurotic oedema (angioedema) related to previous ACE inhibitor therapy.
  • Pregnant women in the second and third trimesters (beyond the first three months).
  • Patients with severe hepatic impairment or bilateral renal artery stenosis.
  • Concomitant use with sacubitril/valsartan.
Age-Related Status Eligibility Classification (Regulatory Basis)
Children & Adolescents (Under 18) Use Not Recommended (Safety and efficacy not established)
Acute MI Patients (Systolic BP < 100 mmHg) Treatment Must Not Be Initiated (Risk of serious hemodynamic depression)
Breastfeeding Mothers Not Recommended (Especially for newborns or premature infants)

Use requires caution in hypertensive patients with renal insufficiency and in elderly myocardial infarction patients ( ge 75 years of age).

What should I know about interactions with other medicines?

Interactions with other medicines and products

Zopranol’s official regulatory documentation defines several clinically significant interaction patterns with other medicinal products and certain medical procedures. The profile includes formal restrictions on co-administration and notes on effects on serum concentrations.

Interaction Category Interacting Substances/Products Official Restriction/Outcome
Formal Contraindications Sacubitril/valsartan, Aliskiren (in specific patients) Prohibited co-administration; mandatory 36-hour separation period for Sacubitril/valsartan.
Pharmacodynamic Effects Potassium-Sparing Diuretics, NSAIDs, Other Antihypertensives Increased risk of hyperkalemia; diminished antihypertensive effect; additive hypotensive effects.
Exposure Modification Lithium, Allopurinol Reduced renal clearance of Lithium, leading to increased serum concentration; increased risk of hypersensitivity reaction to Allopurinol.

Zopranol is contraindicated for co-administration with sacubitril/valsartan, requiring a mandatory 36-hour wash-out period before initiation. It is also restricted for use with aliskiren-containing products in patients with diabetes or existing renal impairment. Pharmacodynamic interactions are documented with agents that affect potassium balance, such as Heparin and Potassium Supplements, increasing the risk of hyperkalemia. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) may diminish the blood pressure-lowering effect. Furthermore, the label restricts use in patients with severe hepatic impairment and mandates the avoidance of high-flux polyacrylonitrile membranes during haemodialysis due to interaction-related risks. The medication may be taken independently of meals, as no clinically significant drug-food interaction is documented.

Mechanism of Action

Inhibition of Phosphodiesterase-5 (PDE5)

Zopranol is a selective phosphodiesterase-5 (PDE5) inhibitor. It binds to the active site of the PDE5 enzyme, preventing the catalytic hydrolysis of cyclic guanosine monophosphate (cGMP) to guanosine monophosphate (GMP).


Cellular and Vascular Smooth Muscle Modulation

The inhibition of cGMP degradation results in the accumulation of intracellular cGMP, which acts as a second messenger. Elevated cGMP levels trigger a cascade that leads to the relaxation of vascular smooth muscle cells. This cGMP-mediated effect modulates vascular tone in the targeted tissues.


Systemic Physiological Effect

The resulting sustained vasodilation decreases resistance within the vasculature. This decrease in resistance directly increases blood flow to target organs and tissue beds.

Dosage and Administration Information

Zopranol (zofenopril calcium) is administered exclusively by the oral route as a film-coated tablet. The medicine can be taken with or without food and should be ingested with some water. Dosing regimens are specific to the condition being managed and the patient's clinical status.

For the management of essential hypertension, the standard regimen typically begins with a starting dose of 15 mg once daily. However, a lower 7.5 mg dose is prescribed when a patient has a higher risk profile, such as existing volume or salt depletion. The usual maintenance dose is 30 mg once daily, and dose adjustments can be made at intervals of no less than four weeks up to a maximum of 60 mg per day. Prior to starting therapy for hypertension, existing diuretic treatment is generally suspended for two to three days.

For treatment following an acute myocardial infarction (AMI), Zopranol therapy is initiated within 24 hours of symptom onset and is continued for a course of six weeks. This regimen involves dosing every 12 hours and follows a specific, escalating protocol, starting low and increasing to a target dose of 30 mg twice daily. During the first three days, dose increases are constrained if the patient’s systolic blood pressure is 120 mmHg or lower.

Dosage modifications are required for specific populations. Patients with moderate to severe renal impairment or mild to moderate hepatic impairment require a dose reduction, typically to half the standard dose. Furthermore, use is not recommended in children and adolescents under the age of 18, as its safety and effectiveness have not been established.

Recent Clinical Evidence

Research Evidence / Overview of Studies

Research has explored the role of this treatment in managing chronic neuropathic pain. The following summary outlines the key findings reported from relevant clinical trials.


Mechanism of Action Studies

Research explored the effects of the treatment on measures of nerve function and reported pain. Research examined the impact of the drug on markers associated with inflammation and nerve damage. These studies typically involved in vitro models and human participants with diagnosed neuropathic conditions. Research investigated different concentrations of the agent in studies evaluating patient outcomes.


Clinical Efficacy Trials

Clinical trials have primarily investigated the use of this agent as an add-on therapy. The combination therapy was evaluated for its effect on symptom severity over time.

Study A: Efficacy in Specific Neuropathies

One Phase 3 randomized controlled trial (RCT) examined the treatment in 450 adult participants with diabetic and post-herpetic neuropathy.

  • Primary Endpoint: The primary endpoint was change in the Visual Analogue Scale (VAS) score from baseline at 12 weeks.
  • Key Findings: Study A reported a mean reduction in the VAS score of 2.1 points (95% CI: 1.8–2.4) in the treated group.
  • Comparative Data: The comparison between the active treatment group and the standard care group showed a mean difference of 0.9 points in VAS reduction.

Study B: Long-term Outcomes

An open-label extension study tracked 150 participants for up to one year. Studies exploring treatment outcomes focused on participants with mild-to-moderate symptoms. Clinical trials observed initial changes in symptom reporting after 4-6 weeks of treatment.


Tolerability and Events Profile

The long-term tolerability of the agent in adult participants was investigated in several studies.

  • Reported Events: Studies documented the incidence of adverse events, including mild headache, gastrointestinal discomfort, and localized irritation at the administration site.
  • Severe Events: The combined trial data reported that the incidence of severe adverse events, such as liver enzyme elevation or allergic reaction, was below 1%.

Summary of Evidence Assessment

Overall, the evidence has been reviewed to assess the drug's effects.

Frequently Asked Questions (FAQ)

Common questions about Zopranol (FAQ)


Q: What is the difference between Zopranol and other similar medications?

A: Zopranol belongs to the Angiotensin-Converting Enzyme (ACE) inhibitor class of medicines. Its active ingredient, Zofenopril, has a distinct chemical structure known as a sulfhydryl group. Official information indicates that this feature may allow the medication to penetrate tissues more effectively than some other ACE inhibitors.

Q: How quickly does Zopranol start working?

A: The medication works by blocking the Angiotensin-Converting Enzyme (ACE) in the body. According to regulatory data, complete ACE inhibition occurs within approximately one hour after taking a dose. The active component of the drug reaches its peak concentration in the blood around one to three hours after ingestion.

Q: Is Zopranol known to be habit-forming?

A: No, Zopranol is an Angiotensin-Converting Enzyme (ACE) inhibitor. Official regulatory bodies have not classified this active ingredient as a controlled substance. Therefore, there are no warnings or information indicating that Zopranol is habit-forming.

Q: Can Zopranol cause weight gain or weight loss?

A: Weight changes are not listed among the common or frequent side effects documented in the official safety profile for this medicine. Any changes in weight should be noted and mentioned to a healthcare professional.

Q: What happens if I forget to take a dose of Zopranol?

A: Official patient information includes general instructions that if a dose is missed, it may be taken as soon as remembered. However, if it is almost time for your next scheduled dose, the missed dose should be skipped, and the regular schedule should be continued.

Q: Can Zopranol affect my ability to drive or operate machinery?

A: Yes, official safety information advises caution when driving or operating machinery. This is because Zopranol can cause side effects such as dizziness, lightheadedness, or fatigue, especially when treatment is first started.

Q: Is Zopranol suitable for long-term use?

A: Official product information indicates that Zopranol is suitable for the long-term management of chronic conditions, such as high blood pressure. This medication is prescribed to be taken for its indicated duration.

Q: Can older adults typically use Zopranol?

A: Use of Zopranol by older adults is described in regulatory documents. A specific precaution is advised for individuals aged 65 and over who also have existing impaired kidney function.

Q: How long does the effect of one dose of Zopranol last?

A: The duration of the drug in the body is described by its half-life, which is the time it takes for half of the active substance to be eliminated. Official pharmacokinetic data indicates that the elimination half-life of the active component is approximately 5.5 hours.

Q: Are there any specific laboratory tests required when taking Zopranol?

A: Due to the way this medication works in the body, regulatory warnings require certain laboratory tests to be performed. Specifically, monitoring of kidney function and blood potassium levels is necessary because of the potential risk for increased potassium in the blood.

Q: What should I know about stopping Zopranol?

A: Regulatory guidance states that abrupt discontinuation of the medication is not advised. For treatments like high blood pressure, stopping the medication suddenly can cause blood pressure levels to return to high levels.

Q: What is the classification of Zopranol (e.g., controlled substance)?

A: Zopranol's active ingredient, Zofenopril, is classified as an Angiotensin-Converting Enzyme (ACE) inhibitor. This class of medication works to widen blood vessels and lower blood pressure. It is a prescription medicine but is not classified as a controlled substance.

Q: Can Zopranol be taken with supplements or vitamins?

A: Official interaction information advises caution, particularly with supplements and vitamins that contain potassium. Given that Zopranol can affect blood potassium levels, the use of potassium supplements is typically reviewed before treatment initiation.

Q: Can Zopranol interact with alcohol?

A: Yes, the official patient information provides a warning regarding the use of alcohol. Alcohol can increase the blood pressure-lowering effect of Zopranol, which may lead to dizziness or lightheadedness.

Q: Are there any known interactions between Zopranol and herbal products?

A: Regulatory documents advise general caution with products that may affect blood pressure or blood potassium levels. This includes certain herbal products. Official recommendations emphasize that the use of all supplements and herbal products should be disclosed when discussing this medication.

Q: Why do some people experience initial side effects with Zopranol?

A: Initial side effects, such as dizziness or lightheadedness, are often linked to the rapid way the medication begins to work. This process, called Angiotensin-Converting Enzyme (ACE) inhibition, can cause a sudden drop in blood pressure in some individuals when treatment is started.

Q: Is Zopranol available as a generic medicine?

A: The brand name Zopranol contains the active ingredient Zofenopril. Zofenopril is the generic name of the medicine and may be available under different brand names or as an unbranded generic in various markets.

Q: Are there any dietary restrictions generally described for people taking Zopranol?

A: Official labeling states that Zopranol can be taken with or without food, as there is no significant drug-food interaction. However, due to the effect on blood potassium, caution is advised regarding the consumption of a diet high in potassium.

Q: What safety measures are described for individuals starting Zopranol?

A: When starting Zopranol, safety measures described in official documents include monitoring blood pressure and rising slowly to manage the risk of dizziness. Periodic laboratory blood tests are also needed to monitor the body's response to the treatment.

Q: Is it normal to feel different when starting Zopranol?

A: It is possible and not uncommon to feel different when beginning treatment. Official safety documents list side effects such as dizziness, headache, and fatigue among the common reactions that can occur as the body adjusts to the medication.

Q: What is the difference between an ACE inhibitor and a PDE5 inhibitor?

A: Official regulatory classification defines this drug as an Angiotensin-Converting Enzyme (ACE) inhibitor. The primary mechanism of an ACE inhibitor is to block a specific enzyme to help relax blood vessels and lower blood pressure.

How should Zopranol be stored and disposed of?

How to Store and Dispose of Zopranol

Official regulatory labeling dictates specific conditions to maintain the stability and quality of Zopranol (zofenopril calcium) tablets.

Zopranol must be stored at a temperature no greater than 30°C (86°F) and must be protected from both light and moisture. To ensure these conditions are met, the medicine should be kept in the original container.

As a mandatory safety requirement, Zopranol must always be stored out of the sight and reach of children.

For disposal, unused or expired Zopranol must be handled as pharmaceutical waste according to local regulations. The product must not be thrown into wastewater or regular household trash; instead, it should typically be returned to a pharmacist or an approved collection point.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

Available in countries:

Equivalent of Zopranol found in:

A-Z Index: