Panagra

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Medically reviewed

Marina Burgos

Last updated on 22/12/2025

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 Panagra

What is Panagra? Definitional Overview

Property Description
Active Ingredient Sildenafil Citrate
Form Film-coated tablet
Pharmacological Class Selective Phosphodiesterase Type 5 (PDE5) Inhibitor
General Purpose To facilitate vasodilation and enhance blood flow
Origin Synthetic compound

Defining Panagra: Composition and Pharmacological Class

Panagra is a prescription-only synthetic medication whose active ingredient is Sildenafil Citrate, and it is classified as a Selective Phosphodiesterase Type 5 (PDE5) Inhibitor. The drug is a single-ingredient product, chemically known as a pyrazolo[4,3-d]pyrimidin-7-one derivative. The drug's therapeutic foundation is clinically recognized for its highly targeted mechanism of blocking the PDE5 enzyme. This mechanism differentiates Panagra from other vascular agents by providing a specific effect on the circulatory system.

Physical Form, Origin, and Therapeutic Context

The Panagra brand is an oral medication typically presented as film-coated tablets. This formulation ensures the controlled delivery of the Sildenafil Citrate compound into the systemic circulation. The general purpose of this PDE5 inhibitor mechanism is centered on regulating vascular resistance. This is achieved by facilitating smooth muscle relaxation and inducing vasodilation, which enhances blood flow to targeted physiological systems. This core therapeutic capability allows the medication to improve circulation by relaxing blood vessel walls in scenarios where enhanced tissue perfusion is required.

Regulatory References

  1. Sildenafil: from the bench to the bedside
  2. Sildenafil: MedlinePlus Drug Information

What side effects are possible with Panagra?

Possible Side Effects and Safety Information

The safety profile of Panagra (Sildenafil Citrate) is officially documented by government regulatory authorities, organizing possible reactions by frequency classification and affected System-Organ Class (SOC). These classifications define the officially reported side effects, which are generally related to the medication’s vasodilatory properties.


Frequency-Classified Adverse Reactions

The most frequently reported effects, based on regulatory data, include headache and flushing, classified as Very Common (occurring in ge 1/10 patients). Reactions classified as Common (ge 1/100 to < 1/10) include dizziness, visual color distortions (chromatopsia), blurred vision, dyspepsia, and nasal congestion. Less frequent, or Uncommon reactions, cover effects such as rhinitis, tachycardia, palpitations, nausea, and rash.


Documented Serious Adverse Reactions and Constraints

The official safety information highlights rare but clinically significant reactions, including Non-arteritic anterior ischaemic optic neuropathy (NAION), a cause of vision loss, and Priapism (a prolonged erection lasting over four hours). Rare cardiovascular events, such as myocardial infarction and cerebrovascular haemorrhage, have also been reported.

Regulatory documents outline specific safety constraints. The medicine is strictly contraindicated for concurrent use with any form of organic nitrates. Furthermore, use is generally restricted in patients with severe hypotension (BP < 90/50 mmHg), a recent history of stroke or myocardial infarction, or severe hepatic impairment.

Official labeling notes that the risk of adverse effects, including symptomatic hypotension when co-administered with alpha-blockers, is often linked to exposure timing and dosage levels above 100 mg.

Overdose and Emergency Response

Overdose and When to Seek Help: Official Regulatory Information

Excessive exposure to Panagra (Sildenafil Citrate) primarily results in an exaggeration of known pharmacological effects. Documented manifestations of overdose in high single doses (up to 800 mg) include an increased rate and severity of symptoms such as decreased blood pressure (hypotension), flushing, headache, and dyspepsia. The clinical presentation centers on the exaggeration of these systemic effects.

When Immediate Medical Help Is Required

The official prescribing information mandates immediate medical attention for specific, time-critical events. This includes any erection lasting longer than four hours (priapism), as this condition requires urgent intervention to prevent potential penile tissue damage and permanent loss of potency. Furthermore, immediate medical assistance must be sought for sudden loss of vision, sudden loss of hearing, or any signs suggestive of a severe hypersensitivity reaction.

Supportive Management

Management of Panagra overdose relies on established symptomatic and supportive treatment, as no specific antidote is documented. Due to the drug’s high plasma protein binding, established procedural measures like renal dialysis are not expected to accelerate clearance of the active substance. Hospital monitoring is required for patients presenting with severe or life-threatening manifestations.

Therapeutic Uses of Panagra

Symptomatic Relief for Acute or Episodic Changes

Panagra is commonly used across conditions presenting with acute episodes or those characterized by episodic or fluctuating manifestations. This medicine helps address symptom clusters that may become intense or disruptive, offering supportive relief when symptoms intensify and temporary assistance is needed. This includes managing symptoms related to physical discomfort, systemic imbalance, or heightened physiological activity.


Managing Symptoms That Interfere with Daily Function

This medicine is applied in addressing groups of symptoms that create noticeable functional strain or interfere with daily comfort. Panagra supports general well-being during symptomatic phases and is relevant when supportive symptom management is appropriate, as it assists with maintaining functional stability when symptoms become temporarily overwhelming. It is commonly used when symptoms cluster into patterns requiring symptomatic management.

“Panagra provides support that helps ease the overall symptom burden, assisting patients in coping more steadily with difficult episodes.”

Quick Fact: May assist with Disruptive Symptom Manifestations


Easing the Overall Burden of Discomfort

Panagra is used in areas where additional symptomatic support is needed for symptoms related to physical discomfort or systemic imbalance. It contributes to improved comfort during periods of heightened symptoms, helping patients cope more steadily with difficult or disruptive episodes by easing the overall symptom burden.

Regulatory References

  1. European Medicines Agency (EMA) on the Wording of Therapeutic Indication

Eligibility and Restrictions for Use

Who Can and Cannot Use Panagra? Population Eligibility

The eligibility for using Panagra (Sildenafil Citrate) is strictly defined by official regulatory documentation, outlining the populations that are permitted, restricted, or absolutely contraindicated.


Contraindications and Prohibited Use

Panagra is contraindicated in specific patient populations due to safety risks. Patients must not use this medicine if they are concurrently taking nitrate medications or nitric oxide donors in any form, or if they are using a soluble guanylate cyclase (sGC) stimulator.

Absolute contraindications also include a known hypersensitivity to sildenafil, a history of vision loss due to NAION, or the presence of severe cardiovascular conditions such as recent stroke or myocardial infarction, and hypotension (blood pressure < 90/50 mmHg).


Age and Condition Restrictions

Adult males (18 years and older) are the established eligible population. However, the medicine is not indicated for use in females or pediatric patients.

Use requires caution and consideration of a lower starting dose for older adults (65 years) and patients with severe renal impairment or mild-to-moderate hepatic impairment. Furthermore, use is contraindicated in patients with severe hepatic impairment and those with conditions predisposing to priapism (e.g., sickle cell anemia) or anatomical deformation of the penis require careful assessment.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory profile for Panagra (Sildenafil Citrate) documents interactions based on its metabolic clearance pathway and its physiological effect on blood pressure. Co-administration with Organic Nitrates or Nitric Oxide Donors is strictly contraindicated, as this combination can lead to a severe and dangerous drop in systemic blood pressure. Similarly, the use of Panagra with Soluble Guanylate Cyclase (sGC) Stimulators, such as Riociguat, is also prohibited.

Sildenafil Citrate is primarily cleared by the CYP3A4 liver enzyme. Strong inhibitors of this enzyme, including certain medicines like Ritonavir or Ketoconazole, reduce Panagra's clearance, which significantly increases systemic exposure and plasma levels. For strong inhibitors like Ritonavir, a specific restriction applies, limiting the maximum single dose over a 48-hour period. Conversely, enzyme inducers, such as Rifampin, may decrease exposure.

Pharmacodynamic interactions exist with other vasodilatory agents. Co-administration with Alpha-Blockers or Antihypertensive Agents may result in an additive blood pressure-lowering effect (hypotension). Furthermore, specific substance interactions are noted: Alcohol consumption may increase the potential for symptomatic hypotension, and Grapefruit juice may raise plasma levels. Population-specific notes confirm that patients with severe hepatic or renal impairment experience reduced clearance, leading to increased exposure.

Mechanism of Action

Panagra is an agent that acts primarily on the bone matrix, where it is internalized by osteoclasts through the resorption lacunae. This mechanism requires the P-C-P (phosphorus-carbon-phosphorus) structure, which grants the drug its high affinity for the hydroxyapatite mineral crystal found in bone.

Inside the osteoclast, Panagra functions as a specific inhibitor of the enzyme farnesyl pyrophosphate synthase (FPPS), a key regulatory component of the mevalonate biochemical pathway. Inhibition of FPPS prevents the isoprenylation of essential small GTP-binding proteins, including Rho, Rac, and Rab, which are required for cytoskeletal organization and vesicular trafficking.

The resulting disruption of the cell's internal structure and signaling cascade leads to the loss of the ruffled border—the specialized membrane required for bone dissolution—and ultimately induces programmed cell death (apoptosis) of the osteoclast. This physiological modulation decreases overall bone catabolic output.

Dosage and Administration Information

How to Use Panagra: Official Administration Guidelines

Panagra (Sildenafil Citrate) usage instructions are dictated by two distinct label-based patterns: Episodic Use (on-demand) and Chronic Maintenance Use (scheduled). Adherence to the official route, dosage, frequency, and administration conditions is required.


Administration Schedule and Dosage Limits

Usage Pattern Standard Dose/Route Frequency Constraint Maximum Dose Limit
Episodic Use (Oral Tablets) 50 mg (initial); range 25 mg to 100 mg. Maximum of once per day. 100 mg per dose.
Chronic Maintenance (Oral Tablets) 20 mg. Titratable up to 80 mg. Three times a day (TID). 80 mg TID.

For episodic use, the dose should be taken from 30 minutes to 4 hours prior to activity. Chronic maintenance doses must be separated by a time interval of 4 to 6 hours.


Special Administration Conditions

  • Route: The primary route is oral. An intravenous (IV) bolus injection is an approved alternative for chronic use when oral intake is temporarily not possible, typically dosed at 10 mg TID.
  • With/Without Food: Panagra may be taken with or without food; however, a high-fat meal may lead to a delayed onset of action.
  • Preparation: Oral suspensions (if used for chronic treatment) require reconstitution with water and must be measured using a calibrated device.
  • Population Adjustments: A reduced starting dose of 25 mg is advised for the episodic regimen in patients with severe renal impairment (creatinine clearance <30 mL/min) or hepatic impairment (e.g., cirrhosis). A lower starting dose may also be considered for older adults (age ≥ 65 years).
  • Missed Dose (Chronic Use): If a scheduled dose is missed, take the next dose at the regularly scheduled time; do not take two doses at the same time.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Panagra

Evidence for use in Episodic Functional Strain (Erectile Dysfunction)

Research for Panagra's active ingredient was studied for conditions characterized by functional limitations, often referred to as erectile dysfunction (ED), and has focused primarily on highly controlled randomized clinical trials (RCTs). These studies were used in research exploring how symptoms change over time, with measurements taken over defined, short time intervals. The outcomes used to monitor the studies included patient-reported outcomes describing perceived discomfort and standardized questionnaires designed to assess measurements of function.

Studies monitored these functional outcomes and reported measurements of change in scores during the study period, relative to participants who received a placebo. Findings describe patterns observed in the studies related to the frequency of attempts and successful sexual activity, as defined by patient-reported outcomes. Reported observations noted that the presence of physical or sexual stimulation was associated with the patterns of change measured in the functional scales.

Evidence for use in Systemic Vascular Resistance Imbalance (Pulmonary Arterial Hypertension)

Panagra was evaluated in studies focusing on Pulmonary Arterial Hypertension (PAH), a condition involving periods of heightened symptoms related to systemic or functional imbalance. Research examined the medicine in large RCTs over short-term periods, with further studies continuing observation for up to a year or more. The outcomes studied were focused on outcomes related to physiological strain or stress, such as measuring functional exercise capacity using the Six-Minute Walk Distance (6MWD), and assessing changes in standard measures of disease severity (WHO Functional Class).

Short-term trials reported measurements of change in the 6MWD when compared to placebo in adult populations. Findings describe patterns observed in the studies related to changes in the WHO Functional Class in some patients. Studies monitored the time it took for the patient's condition to be noted as clinically worsened. Long-term studies contribute to the broader evidence landscape by providing context on how outcomes reflecting daily functioning or activity level were monitored during continued observation.

What is Still Uncertain About Panagra in Research

A key limitation across several indications is that the long-term effects are not fully established by high-quality, blinded data. The durability of changes in patient-reported outcomes beyond one year is largely understood through open-label studies, where certainty remains lower.

Research in the pediatric population yielded mixed findings and concerns regarding a potential differential signal at higher dosages. This indicates that for certain populations, data for these groups remain insufficient to define a clear and universal evidence pattern. The research contributes to understanding symptom patterns but does not determine whether an individual will respond similarly.

Frequently Asked Questions (FAQ)

Common questions about Panagra (FAQ)


Q: Can Panagra be taken with food or does it matter?

The official regulatory documentation for Panagra indicates that the drug may be taken with or without food. However, if the medication is taken with a high-fat meal, the official product information indicates that this may lead to a delayed onset of action.


Q: How long does it typically take for Panagra to start working?

Official guidelines for on-demand (episodic) use advise that the medication should be taken within a window of 30 minutes to 4 hours prior to activity. This timeframe is outlined in the drug's administration guidelines.


Q: Is Panagra safe for women who are pregnant?

Panagra is not indicated for use in female patients for its primary functional use. For the approved pulmonary hypertension use, official sources note that safety during pregnancy has not been established. Some international regulatory bodies have assigned a pregnancy category based on limited human exposure data.


Q: What are the most serious but rare side effects of Panagra?

The serious but rare reactions documented in official safety information include Non-arteritic anterior ischaemic optic neuropathy (NAION), a form of vision loss, and Priapism (an erection lasting over four hours). Rare cardiovascular events such as myocardial infarction (heart attack) and cerebrovascular haemorrhage have also been reported in regulatory documents.


Q: Are there any dietary restrictions while using Panagra?

Regulatory documents mention specific interactions with certain food elements. Co-administration with Grapefruit juice may increase the drug's plasma levels, as noted in official interaction documents. Additionally, the consumption of Alcohol may increase the potential for symptomatic hypotension (a notable drop in blood pressure).


Q: What should I avoid eating while taking Panagra?

Official product information notes a potential interaction with Grapefruit juice due to its effect on drug levels in the body. Official administration guidelines also mention that taking the medication with a high-fat meal may result in a delayed onset of action.


Q: Is Panagra different from other drugs used for the same condition?

Panagra's active ingredient, Sildenafil Citrate, is officially classified as a Selective Phosphodiesterase Type 5 (PDE5) Inhibitor. This means the drug works by blocking the PDE5 enzyme to promote the relaxation of blood vessels and facilitate vasodilation, which distinguishes it from drugs with different chemical classes or mechanisms of action.


Q: Is Panagra a pain reliever?

No, Panagra is not classified as a pain reliever. Its pharmacological class is a Selective Phosphodiesterase Type 5 (PDE5) Inhibitor. The general purpose of this mechanism is to affect the circulatory system by facilitating vasodilation and enhancing blood flow.


Q: Is Panagra addictive or habit-forming?

Official regulatory records, such as the US Controlled Substances Act, classify the active ingredient in Panagra as not a controlled substance. This classification means the active ingredient is not designated as having a high potential for abuse or dependence under the Controlled Substances Act.


Q: What kind of research studies have been done on Panagra?

The research supporting the drug's uses is primarily based on highly controlled randomized clinical trials (RCTs). These studies were designed to assess functional changes and patient-reported outcomes over short-term periods. Further studies have continued observation over longer periods, sometimes up to a year or more.


Q: Is Panagra suitable for children?

Panagra is not indicated for use in pediatric patients for its episodic functional use. Furthermore, official research information notes that studies conducted in the pediatric population yielded mixed findings and raised concerns regarding a potential differential signal when higher dosages were used.


Q: What is the half-life of Panagra (how long does it stay in the body)?

According to the pharmacokinetics section of the official prescribing information, the terminal half-life (t1/2) of the active ingredient is approximately 3–5 hours. This figure describes the time it takes for the concentration of the medication in the plasma to be reduced by half.


Q: Does Panagra have a generic version available?

Yes, the active ingredient in Panagra, which is Sildenafil Citrate, is available from various manufacturers in generic formulations. The availability and prescribing rules for generic products are subject to local regulatory approval in each country.


Q: What is the maximum time people typically stay on Panagra?

While short-term efficacy trials were the primary basis for the drug's approval, long-term studies have been conducted. These studies have monitored patients for up to a year or more, providing context on outcomes during extended observation.


Q: Is Panagra a controlled substance?

No, Panagra is not classified as a controlled substance. Official regulatory records, including the US Controlled Substances Act, indicate that the active ingredient is not scheduled as a controlled medication.


Q: Does the effectiveness of Panagra decrease over time (tolerance)?

Studies and official information indicate that for long-term, as-needed use, observed patterns suggest the development of tolerance or tachyphylaxis (decreased response) is not a consistent finding.


Q: Is Panagra approved in other countries besides the US?

Yes, the active ingredient, Sildenafil Citrate, has received marketing authorization from many regulatory bodies globally. This includes major governmental agencies such as the EMA (European Medicines Agency) and Health Canada, indicating its approval across multiple regions.


Q: Why are there different doses of Panagra available?

The different doses of Panagra are available because the medication is approved for two distinct usage patterns: Episodic Use (taken on demand) and Chronic Maintenance Use (scheduled). Each pattern has specific guidelines for the starting dose and the maximum dose limit.


Q: Is it normal to feel tired when starting Panagra?

The official adverse event profile lists headache and flushing as the most common effects. While dizziness is also listed as a common reaction, tiredness (fatigue or somnolence) is not among the most frequently reported effects in the official documentation.


Q: Can Panagra be taken with other prescription drugs?

Panagra is contraindicated (absolutely forbidden) with certain prescription drugs, including organic nitrates, nitric oxide donors, and sGC stimulators. Regulatory information also notes that caution is required when co-administering with other agents, such as Alpha-Blockers, due to a potential additive blood pressure-lowering effect.


Q: Is Panagra a long-term or short-term medication?

The official labeling supports two distinct usage patterns: Episodic Use (on demand) and Chronic Maintenance Use (scheduled). Research covers both short-term efficacy to support its episodic use and prolonged observation periods for its scheduled use, depending on the approved indication.


Q: What does the manufacturer say about Panagra's use?

Official manufacturer-provided materials describe the drug's intended uses, which are centered on facilitating vasodilation and enhancing blood flow for two approved conditions. The materials also provide detailed administration guidelines and lists of potential side effects, consistent with regulatory labeling.

How should Panagra be stored and disposed of?

Storage and Disposal Requirements for Panagra

Official regulatory documents define strict conditions for the storage and final disposal of Panagra (Sildenafil Citrate) film-coated tablets to maintain product quality and safety.


Storage Conditions

Panagra must be stored at controlled room temperature, generally not above 30°C (86°F), and protected from moisture. The medication must be kept in its original container and the container should be kept tightly closed.


Child Safety and Disposal

It is mandatory to keep this medicine out of the sight and reach of children at all times.

Expired or unused Panagra must not be disposed of by throwing it away in household waste or flushing it down a toilet. Disposal must be performed in accordance with local regulations or by returning it to a pharmacist for proper pharmaceutical waste handling.

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

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