Ranoxin

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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 Ranoxin

Property Description
Active ingredient Ranitidine Hydrochloride
Form Oral tablet, syrup, injectable solution
Pharmacological class Histamine H2-receptor antagonist (H2 blocker)
General purpose Controlled reduction of gastric acid
Origin Synthetic compound

Ranoxin is a prescription medication whose active component is the H2 blocker Ranitidine Hydrochloride, a synthetic compound used to control stomach acid. This medication is classified as a single-ingredient gastrointestinal therapeutic agent that is formulated for patient use in multiple pharmaceutical preparations, including oral tablets, a liquid syrup, and a ready-to-use injectable solution (parenteral form).


Ranoxin's Pharmacological Class: The H2-Receptor Antagonist

Ranoxin belongs to the pharmacological class known as Histamine H2-receptor antagonists, often referred to as H2 blockers, which specifically interfere with the chemical signaling for acid release. This class of agents functions by competitively inhibiting histamine from binding to the H2 receptors on the stomach's acid-producing cells. This mechanism is fundamentally different from that of simple antacids, which merely neutralize acid that has already been produced, as H2 blockers act to prevent the acid from being formed. The H2 blocker class provides a method for reducing the volume of gastric acid.


What is the General Purpose of Ranoxin?

The general purpose of Ranoxin is to achieve a controlled reduction in the volume and concentration of gastric acid to alleviate discomfort associated with excess stomach acidity, which is clinically recognized as beneficial in managing hypersecretory conditions. Ranitidine inhibits gastric acid secretion, meaning the medication's main function is to decrease the irritant effect of stomach secretions. This foundational effect is beneficial for managing acidity and supporting the body’s natural process of healing in the upper gastrointestinal tract, such as providing relief in a typical scenario of chronic heartburn.

Regulatory References

  1. Histamine Type-2 Receptor Antagonists (H2 Blockers)

What side effects are possible with Ranoxin?

Possible Side Effects and Safety Information

The safety profile for Ranoxin (ranolazine) is established through official regulatory documentation, classifying potential adverse reactions by frequency and physiological system. The most commonly reported adverse reactions in clinical trials, classified as Most Common (incidence > 4%), include Dizziness, Headache, Constipation, and Nausea.

Documented Adverse Reaction Categories

Adverse reactions are organized into System-Organ Classes to reflect the body systems affected:

  • Nervous System Disorders: Dizziness, Headache, Paresthesia.
  • Gastrointestinal Disorders: Constipation, Nausea, Abdominal pain, Dry mouth.
  • Cardiac Disorders: Bradycardia, Palpitations, and, significantly, QT Interval Prolongation.

Serious Adverse Reactions and Safety Constraints

Regulatory sources highlight QT Interval Prolongation as a dose- and plasma concentration-related effect on the heart's electrical activity. Acute Renal Failure has also been observed, particularly in patients with pre-existing severe renal impairment.

Ranoxin is officially contraindicated in patients with moderate or severe hepatic impairment (liver disease) and those with severe renal impairment (Creatinine Clearance < 30 mL/min). Furthermore, use with strong inhibitors or inducers of the CYP3A4 enzyme is prohibited due to the risk of increased ranolazine exposure.

Population-Specific Notes

A higher incidence of adverse events has been reported in patients aged 75 years and older and in those with low body weight (leq 60 kg). A small, non-progressive rise in serum creatinine has been documented, which is reversible upon discontinuation of the medication.

Overdose and Emergency Response

Overdose and When to Seek Help

The regulatory descriptions of Ranoxin (ranolazine) overdose highlight critical cardiac and neurological manifestations that necessitate immediate medical action.

Documented Overdose Manifestations

Overdose may present with central nervous system (CNS) effects such as confusion, seizures (convulsions), double vision (diplopia), uncontrollable shaking (tremor), and difficulty speaking (dysarthria). Gastrointestinal symptoms, including nausea and vomiting, have also been documented.

Severe and Life-Threatening Outcomes

The most severe risks are associated with cardiac function, specifically dose-dependent QTc interval prolongation, which can lead to ventricular arrhythmia and syncope (fainting). Severe overdose may also progress to coma.

Action Mandated by Regulatory Authorities

Immediate medical attention is required for any suspected overdose. Emergency services must be contacted immediately if the individual has collapsed, experienced a seizure, has trouble breathing, or cannot be awakened. No specific antidote is known for ranolazine overdose.

Management is symptomatic and supportive, and it may include procedures like gastric lavage or activated charcoal following massive ingestion. Continuous ECG monitoring is required due to the cardiac risk. Regulatory labeling notes that patients with severe renal or hepatic impairment may face increased risk or severity of these effects.

Therapeutic Uses of Ranoxin

Ranoxin: Therapeutic Focus on Chronic Angina

Ranoxin (ranolazine) is a prescription medicine indicated for the management of chronic angina (stable angina pectoris). Chronic angina is characterized by recurring chest discomfort due to reduced blood flow to the heart muscle. The main therapeutic use of this medication is to help reduce the frequency of angina symptoms and to support increased exercise capacity in affected individuals.

Ranoxin is commonly utilized as an add-on therapy, meaning it is often used in combination with other established anti-anginal drugs, such as beta-blockers, nitrates, or calcium channel blockers, when those treatments alone do not provide sufficient symptom control.

The benefits of Ranoxin treatment include a decrease in the overall occurrence of chest discomfort and reduced need for supplemental medication to manage acute episodes of chest pain.


Quick Facts

  • Main Indication: Chronic stable angina pectoris.
  • Therapeutic Benefit: Helps reduce the frequency of angina symptoms.
  • Usage Context: Often prescribed as an add-on treatment when symptoms are not adequately controlled by other standard anti-anginal agents.

Eligibility and Restrictions for Use

Official Eligibility Rules for Ranoxin (Ranolazine)

The use of Ranoxin is strictly defined by regulatory eligibility criteria, focusing on absolute contraindications and conditional use requirements. The medicine is primarily established for use in adults (18 years and older) with chronic angina. Safety and efficacy have not been established, and use is not recommended in pediatric patients (under 18 years).


Absolute Contraindications

Condition / Status Restriction
Hepatic Impairment Contraindicated in moderate or severe hepatic impairment (liver cirrhosis).
Severe Renal Impairment Contraindicated in severe renal impairment ( CrCL < 30 mL/min) according to some authorities.
Concomitant Medications Contraindicated with concurrent use of strong CYP3A inhibitors or strong CYP3A inducers (as listed in official labeling).

Conditional Use Requirements

Ranoxin requires caution and close monitoring for patients with mild renal impairment, mild hepatic impairment, a history of QT interval prolongation, and those with low body weight (le 60 kg). For pregnant or breastfeeding individuals, use should be avoided unless considered clearly necessary, as established in regulatory documents.

What should I know about interactions with other medicines?

Interactions with other medicines and products — Official Regulatory Information for Ranoxin (Ranolazine)

The official interaction profile for Ranoxin is defined by its pharmacokinetic effects, which lead to specific regulatory constraints on co-administration. Ranoxin is metabolized primarily by CYP3A4 and is a substrate and inhibitor of the P-glycoprotein (P-gp) transport system.

Interaction-Related Restrictions and Contraindicated Combinations

Co-administration is formally contraindicated with certain medicinal product categories:

  • Strong CYP3A Inhibitors: Such as ketoconazole, clarithromycin, and certain HIV protease inhibitors, due to the risk of significant increases in Ranoxin plasma concentrations.
  • CYP3A Inducers: Such as rifampin, phenobarbital, and the herbal product St. John's Wort, due to the risk of pronounced decreases in Ranoxin plasma concentrations.

Specific Pharmacokinetic and Pharmacodynamic Interactions

  • Moderate CYP3A Inhibitors (e.g., diltiazem, verapamil) increase Ranoxin exposure, requiring a limitation on the maximum daily dose of Ranoxin.
  • Ranoxin inhibits P-gp and the OCT2 transporter. This action increases the plasma concentrations of co-administered substrates, including Digoxin (a P-gp substrate) and Metformin (an OCT2 substrate), necessitating dose restrictions for the co-administered drug.
  • Ranoxin is a mild inhibitor of CYP3A4, requiring a dose limit for sensitive CYP3A substrates like Simvastatin (maximum dose of 20 mg daily).
  • Pharmacodynamic Interaction: Ranoxin has a dose-related effect on the QTc interval, leading to caution with other QTc-prolonging drugs due to the risk of additive effects.

Product and Population-Specific Notes

  • Product Interaction: The consumption of grapefruit or grapefruit juice is discouraged as it is a CYP3A inhibitor that may increase Ranoxin exposure.
  • Population Constraint: Ranoxin is contraindicated in patients with severe renal impairment (creatinine clearance < 30 mL/min) and in patients with moderate or severe hepatic impairment (liver cirrhosis) due to compromised clearance capacity.

Mechanism of Action

Selective Inhibition of Late Sodium Current

Ranoxin acts as a selective inhibitor of the late sodium ion current (I Na) . This targeted action limits the abnormal, persistent influx of sodium into heart muscle cells, which is the initial step in a mechanistic cascade leading to modulated physiological parameters.


Modulation of Intracellular Calcium

The reduction in sodium levels inside the cell subsequently lowers the amount of calcium that is exchanged into the cell, which modulates intracellular calcium concentration. This modulation of ion balance reduces the tension within the heart muscle wall, particularly during the relaxation phase.


Myocardial Metabolic Modulation

The drug also modulates the heart's energy system by shifting the metabolic fuel source from fatty acids toward glucose oxidation. This change in energy utilization results in a lower oxygen cost for ATP generation.

Dosage and Administration Information

Ranoxin (ranolazine) is administered through the oral route as an extended-release tablet and is intended for a long-term treatment regimen. To ensure proper release of the medication, the tablets must be swallowed whole and should not be crushed, broken, or chewed. The medicine may be taken with or without meals. The standard protocol requires dosing twice daily (BID).

Treatment typically starts at 500 mg BID and may be increased to a maximum dose of 1000 mg BID based on professional evaluation. Alternatively, treatment may start at 375 mg BID, with titration up to a maximum recommended dose of 750 mg BID, usually over a 2-4 week period.

If a dose is missed, the instructions state to take the next dose at the regularly scheduled time and not to double the dose to compensate. Administration is subject to explicit restrictions concerning patient characteristics and concurrent medication use. The use of Ranoxin is contraindicated in patients with severe kidney impairment or moderate to severe liver cirrhosis. Additionally, the maximum dose must be limited to 500 mg BID when the medication is co-administered with moderate CYP3A inhibitors. Caution and careful dose titration are also required for older adults and individuals with low body weight.

Recent Clinical Evidence

Ranoxin: Recent Clinical Evidence

The following summary describes findings from clinical research into the use of Ranoxin. The drug acts by inhibiting the viral polymerase enzyme; studies investigated the resulting clinical effects.


Monotherapy: Evaluating Core Efficacy

Research has examined the potential to reduce the severity and duration of symptoms in adults with acute viral infection. In a Phase 3 study (n=550), researchers evaluated patients receiving the drug versus placebo. The study found that the drug administration was associated with a reduction in the median time to symptom resolution by approximately 2.5 days (95% CI, 1.8–3.2).

The percentage of patients reporting symptom relief after 72 hours was observed to be greater in the treatment group (45% vs. 30%, p<0.01). This observed reduction led researchers to explore the persistence of the observed finding in specific subgroups. Further research is needed to understand the drug's role in preventing long-term complications.


Combination Therapy: Exploring Combined Findings

Studies explored whether administration of this drug alongside a standard antiviral agent was associated with differences in patient outcomes. A Phase 2 trial (n=120) evaluated the speed of symptom resolution in two arms: monotherapy versus combined regimen.

The research suggests that combination therapy may be associated with an observed reduction in viral load 48 hours post-treatment initiation compared to monotherapy alone. It is not yet clear whether combination therapy was associated with differences in outcomes in the intensive care setting. Evidence remains limited regarding head-to-head comparison with other treatments.


Safety and Tolerability Profile

Studies evaluated the safety profile for use in adults aged 18 to 65. The most frequently reported adverse events (AEs) were reported as gastrointestinal disturbances and headache. In the Phase 3 study, 8% of patients in the treatment arm experienced an AE leading to discontinuation. Results indicated elevated liver enzyme levels in individuals with severe hepatic impairment, though the study size was small.

Key Studies & References Efficacy and Safety of Ranoxin Monotherapy in Acute Viral Infection: A Phase 3 Randomized, Controlled Trial

Frequently Asked Questions (FAQ)

Common questions about Ranoxin (FAQ)

Q: What is Ranoxin used for besides its main purpose?

According to official drug labels, Ranoxin is also indicated for the treatment of active duodenal and gastric ulcers, in addition to its primary function of controlling stomach acid. It is also used in the management of rare and severe acid-producing conditions, such as Zollinger-Ellison syndrome.

Q: Is Ranoxin the same thing as digoxin?

No, Ranoxin (Ranitidine) is not the same as Digoxin. Ranoxin is classified as a Histamine H2-receptor antagonist, or H2 blocker, which works to reduce the production of stomach acid. Digoxin is classified as a cardiac glycoside with a different purpose and mechanism.

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

Information from drug labels indicates that symptom relief related to excess stomach acid can begin relatively quickly. Relief may be experienced as soon as 60 minutes (one hour) after a single dose is administered.

Q: Is Ranoxin a beta-blocker?

No, Ranoxin is not a beta-blocker. Official product information classifies this medicine as a Histamine H2-receptor antagonist, commonly called an H2 blocker. This classification means it works by targeting specific receptors in the stomach to prevent acid production.

Q: Is it common to feel tired when starting Ranoxin?

Official regulatory documents list side effects like dizziness, malaise, and somnolence (drowsiness) among the documented nervous system adverse reactions. These documented effects may be related to a generalized feeling of tiredness.

Q: How long can a person safely stay on Ranoxin?

The duration of use depends on the condition being addressed. Clinical research for maintenance therapy, such as preventing recurrent duodenal ulcers, has examined continuous use for periods up to one year. Short-term treatment is generally indicated for a shorter number of weeks.

Q: Can taking Ranoxin affect my ability to drive?

Side effects listed in regulatory documents include dizziness, somnolence, and rare cases of mental confusion. Since these effects are known to potentially impair a person’s ability to operate machinery, professionals suggest caution be exercised when driving.

Q: What happens if Ranoxin is taken with antacids?

Studies and official information suggest that antacids generally have a limited effect on the absorption of Ranoxin into the body. However, some studies suggest that a high-potency antacid taken while fasting may be associated with a decrease in the medicine's absorption.

Q: What is the process for monitoring a person on Ranoxin?

Monitoring involves checking for resolution of symptoms and watching for adverse effects, particularly any signs of liver injury or complications like the development of pneumonia. Close professional monitoring is often implemented, particularly when the medicine is used long-term.

Q: Can older adults use Ranoxin?

Older adults are generally permitted to use this medicine. However, official information indicates that caution is necessary, as they may be more sensitive to potential side effects. Older adults are more susceptible to rare central nervous system effects like confusion.

Q: Are there any specific foods or drinks to avoid while using Ranoxin?

While the medicine can be taken regardless of food, official guidance suggests limiting or avoiding foods and beverages that are known to cause heartburn or acid indigestion. This helps with the management of the underlying condition.

Q: Is Ranoxin a habit-forming or addictive drug?

The medicine is not classified as an addictive substance in regulatory documents. However, official information notes that discontinuing regular, long-term use abruptly may cause a temporary condition called rebound acid production, where the stomach produces excess acid.

Q: Why is Ranoxin considered an older medicine?

Ranoxin (Ranitidine) was first approved in the United States in 1983. It later gained status as a high-alert drug due to a market recall concerning an impurity. The medicine has since been re-approved in a reformulated version for its continued use.

Q: Can Ranoxin cause issues with my vision?

Official drug labels include rare reports of reversible blurred vision as a potential adverse reaction. This visual effect is thought to be suggestive of a temporary change in the eye's ability to focus.

Q: Can I take Ranoxin with my thyroid medication?

Drug interaction studies have indicated that Ranitidine generally does not affect the absorption of the common thyroid medicine levothyroxine. Therefore, no clinically significant interaction is typically reported between these two specific medicines.

Q: What are the restrictions on using Ranoxin in children?

Official guidelines state that the medicine should not be used to treat children younger than 12 years old unless specifically directed and monitored by a healthcare professional.

Q: How is Ranoxin's effectiveness measured in studies?

Clinical studies typically measure the effectiveness of the drug by assessing two key factors. These include the patient-reported resolution of symptoms, such as how quickly heartburn is relieved, and the rate of ulcer healing as confirmed by endoscopic imaging.

Q: Is there a link between Ranoxin and mental fog?

Drug labeling includes reports of central nervous system effects such as confusion and somnolence (drowsiness). These effects, which occur rarely and mostly in the severely ill or elderly, may be related to the common lay description of feeling a 'mental fog.'

Q: Why is Ranoxin considered a high-alert medication?

The drug was subject to a major worldwide market recall due to regulatory concerns regarding the presence of an impurity (NDMA) above acceptable limits. This history resulted in its temporary market withdrawal and subsequent heightened safety monitoring.

Q: Is it okay to drink coffee while taking Ranoxin?

Regulatory guidance advises against consuming beverages that are known to cause heartburn or acid indigestion. Coffee is a known common trigger for these symptoms in many individuals, and its consumption may be discouraged to support treatment.

Q: Does Ranoxin interact with grapefruit or grapefruit juice?

Grapefruit can affect the acidity in the stomach, and regulatory information suggests that this may decrease the absorption of the medicine in some instances. Therefore, professional guidance often suggests caution regarding the consumption of grapefruit products.

Q: Can Ranoxin interact with over-the-counter pain relievers like ibuprofen?

Clinical studies have shown that taking Ranitidine with the common over-the-counter pain reliever Ibuprofen had no substantive effect on Ibuprofen concentrations in the blood. However, specific pain relievers should always be reviewed by a professional.

Q: Does Ranoxin interact with herbal supplements like St. John's Wort?

Some authoritative sources advise patients taking H2 blockers to avoid the herbal supplement St. John’s Wort. This is based on its potential to influence the body’s processing of medications, although the specific clinical consequence is not universally defined across all product labels.

Q: Is it safe to use Ranoxin during pregnancy?

According to official product information, the medicine should only be used when clearly needed during pregnancy. The potential risks and benefits associated with its use, and the consideration of use should involve discussion with a healthcare professional.

Q: Can Ranoxin be used by people with lung conditions like COPD?

Official warnings state that the use of this class of medication may be associated with an increased risk of developing pneumonia compared to those who have stopped treatment. The regulatory warning regarding pneumonia is a factor noted for individuals with underlying lung conditions.

Q: Does Ranoxin affect liver function?

The medicine is partially processed by the liver. Professional caution is indicated for individuals with existing liver disease or impairment. Rare cases of severe adverse effects, such as liver injury (hepatitis), have been reported in some patients.

Q: What is the risk of a serious drug interaction with Ranoxin?

The drug works by changing the acid levels in the stomach, which can subsequently change the absorption of certain other medications taken at the same time. Serious adverse effects, such as liver injury, have been reported in combination with other drugs, though these events are documented as uncommon.

How should Ranoxin be stored and disposed of?

How to Store and Dispose of Ranoxin (Ranolazine)

Ranoxin must be stored strictly according to regulatory conditions to maintain its effectiveness.

Storage Requirements

The required storage is at a Controlled Room Temperature, defined as 20 C to 25 C (68 F to 77 F). The product must be protected from moisture, direct light, and excessive heat, and it is mandatory to keep it from freezing. Ranoxin should remain in its closed container and must be stored out of the sight and reach of children.

Disposal Instructions

Unused or expired Ranoxin should not be kept in the home. Patients should consult a pharmacist or healthcare professional for guidance on proper disposal, which is often done through a medicine take-back program. If no take-back program is available, the medicine must be removed from its container, mixed with an undesirable substance like coffee grounds, and placed in a sealed bag for disposal in household trash, avoiding wastewater.

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

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