Caprol

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Medically reviewed

Laura Arias

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 Caprol

Property Description
Active ingredient Pantoprazole
Form Delayed-Release Tablet, Injection
Pharmacological class Proton Pump Inhibitor (PPI)
Common use Suppression of gastric acid
Origin Synthetic (Substituted benzimidazole derivative)

What is Caprol and How is it Classified? (Definition, Class, Origin)

Caprol is a prescription-only medication defined by its active pharmaceutical ingredient, pantoprazole, and is classified as a Proton Pump Inhibitor (PPI). Pantoprazole is a synthetic substituted benzimidazole derivative, making it a highly specific anti-ulcer agent. This classification is clinically recognized for its effectiveness in managing conditions involving excessive acid production.

Among the PPI class, pantoprazole is often distinguished by its lower propensity for drug interactions, particularly with other medications metabolized by the CYP450 enzyme system, making it a potentially preferred option for patients on multiple long-term medications. This reduced interaction risk is a critical differentiating factor, contributing to the drug's overall safety profile in complex patient populations.


What are the Available Forms of Caprol? (Composition, Form, Delivery System)

Caprol is formulated as a single-ingredient product, centered around pantoprazole sodium sesquihydrate. It is widely available for oral intake as Delayed-Release Tablets or Delayed-Release Granules for Oral Suspension. It is also supplied as a Powder for injection form for intravenous use in clinical settings when oral administration is not possible. The oral forms utilize an enteric-coating, a key technological component that ensures the active substance is protected from corrosive stomach acid, allowing it to reach the small intestine intact for proper absorption. This specialized delivery system is fundamental to achieving the necessary sustained and powerful antisecretory effect.


What is the General Purpose of Caprol? (High-Level Benefit)

The core function of Caprol is to achieve a potent and lasting suppression of gastric acid secretion, thereby dramatically reducing the acid load in the upper digestive tract. This profound antisecretory effect is primarily utilized to mitigate the irritation and inflammation that stomach acid can cause, promoting the healing of the affected tissues, such as the lining of the esophagus and stomach.

Regulatory References

  1. Pantoprazole

What side effects are possible with Caprol?

Caprol's safety profile, based on its active ingredient pantoprazole, is formally defined by regulatory agencies and organized according to both the frequency of occurrence and the physiological system affected.

Frequency-Classified Adverse Reactions

The most frequently documented adverse reactions, officially categorized as common, include headache, diarrhea, nausea, abdominal pain, and flatulence. Reactions classified as uncommon include sleep disorders, dizziness, vertigo, and increased liver enzyme levels. Rare events include hypersensitivity reactions, leukopenia, and thrombocytopenia, while conditions such as interstitial nephritis and hypomagnesemia are classified as having a not known frequency.


Serious Adverse Reactions and Safety Patterns

The regulatory label explicitly documents several clinically significant, though rare, safety concerns. These include the potential for Acute Tubulointerstitial Nephritis (TIN), severe skin reactions like Stevens-Johnson syndrome (SJS), and an increased risk of osteoporosis-related fractures of the hip, wrist, or spine [NIH: MedlinePlus].

Specific risks are tied to the duration of use. Prolonged exposure, typically for one year or more, is associated with the risk of bone fractures and the development of Fundic Gland Polyps. Daily use exceeding three years may lead to Cyanocobalamin (Vitamin B-12) deficiency.


Population-Specific Considerations

Official prescribing information specifies that patients with severe hepatic impairment require monitoring of liver enzyme levels during therapy. Furthermore, co-administration with certain HIV protease inhibitors (such as atazanavir) is contraindicated due to the risk of significantly reduced bioavailability of the antiretroviral medication [FDA Label].

Overdose and Emergency Response

Overdose and when to seek help

The official regulatory profile for Caprol (hydroxyprogesterone caproate) overdose is primarily structured around mandated emergency actions and supportive care. Regulatory documents generally do not detail specific clinical manifestations, symptoms, or signs resulting from an acute overdose event. Overdose information regarding specific severity classifications or dose-related factors is not detailed in the official prescribing information beyond the general caution against exposure to amounts greater than the recommended dose.


Required Emergency Actions

In the event of a suspected overdose, official guidance mandates that you seek immediate medical attention and contact a Poison Control Center right away. This immediate response is required because no specific antidote is known for the effects of hydroxyprogesterone caproate. When seeking help, be prepared to report the amount taken and the time of the event.


Overdose Management and Profile

Management of a Caprol overdose is constrained to symptomatic and supportive treatment. While specific acute overdose symptoms are not listed, the drug's routine use warnings cite potential serious risks, such as thrombotic or thromboembolic disorders. Due to the systemic nature of the medication and the potential for serious complications, hospital observation and continuous monitoring may be required as part of the management protocol. Overdose information regarding specific population-specific considerations is not explicitly detailed in the official labeling.

Therapeutic Uses of Caprol

Caprol: Therapeutic Applications

Caprol (hydroxyprogesterone caproate) has been authorized in certain jurisdictions for use in obstetrics and gynecology. The core therapeutic domain is the management of specific conditions related to a deficiency of the hormone progesterone.

Key authorized uses have included the prevention of recurrent spontaneous preterm birth in women with a history of this event. Additionally, in some countries, Caprol has been approved for the treatment of certain gynecological disorders and fertility-related issues associated with insufficient progesterone levels.

It is critical to note that the effectiveness of Caprol in preventing recurrent premature birth and its benefit-risk profile for other indications have been subject to regulatory review by health authorities. Reviews have been conducted due to concerns over efficacy and potential safety risks, including a possible increased risk of cancer in individuals exposed in utero.

  • Quick Facts: Therapeutic Domains
    • Prevention of recurrent spontaneous preterm birth.
    • Management of specific gynecological disorders.
    • Treatment of fertility issues linked to progesterone deficiency.

For the most current information regarding its safety and authorization status, consult official regulatory guidance and therapeutic overviews provided by relevant health authorities.

Eligibility and Restrictions for Use

The eligibility for using Caprol (Hydroxyprogesterone Caproate) is strictly defined by official regulatory documents, outlining populations who are absolutely prohibited from using the medicine and those who require special caution.

Absolute Contraindications

Caprol must not be used by individuals with certain pre-existing conditions, as these are cited as absolute non-eligibility rules in regulatory labels. Contraindications include a current or past history of thrombosis or thromboembolic disorders, hormone-sensitive cancers (such as breast cancer), active liver disease or liver tumors, and uncontrolled hypertension. Use is also prohibited in patients with undiagnosed, abnormal vaginal bleeding or a known hypersensitivity to the drug.

Age and Conditional Eligibility

The medicine's safety and effectiveness have not been established in pediatric patients (typically under 16) or geriatric patients (65 and over), as these groups lack sufficient regulatory data. Regulatory labeling advises caution and monitoring for patients with conditions sensitive to fluid retention, such as renal or cardiac dysfunction, or those with a history of clinical depression or diabetes.

Pregnancy Status

The medicine's regulatory approval status for the prevention of recurrent spontaneous preterm birth has been withdrawn by the FDA in the United States and recommended for suspension by the EMA in the European Union, which significantly limits eligibility for this indication globally.

What should I know about interactions with other medicines?

The official interaction profile for Caprol (pantoprazole) is defined by its two core domains: pH-dependent pharmacodynamic interference and hepatic metabolism/plasma concentration alterations. This information is based strictly on governmental regulatory documents.

Classification of Interaction Interacting Agents Official Regulatory Outcome
Contraindicated Combinations Rilpivirine-containing products, Atazanavir, Nelfinavir Significantly reduced exposure of the antiretroviral, potentially causing loss of therapeutic effect and drug resistance. Co-administration is formally prohibited or strongly avoided.
Exposure Reduction Ketoconazole, Itraconazole, Oral Iron Salts Reduced absorption and bioavailability due to the elevation of intragastric pH.
Exposure Increase/Altered Parameters Warfarin, Phenprocoumon (Coumarin Anticoagulants) Increased International Normalized Ratio (INR) and Prothrombin Time have been reported, necessitating professional monitoring upon initiation or cessation of Caprol.
Exposure Increase/Toxicity Methotrexate (primarily at high dose) May elevate and prolong serum concentrations of methotrexate, potentially leading to toxicities.

Timing-based rules state that the delayed-release tablets may be taken without regard to food, as co-administration only delays absorption but does not alter the overall extent of absorption. Caprol may also produce false-positive results in some urine screening tests for Tetrahydrocannabinol (THC).

Mechanism of Action

Caprol functions as a competitive inhibitor of angiotensin-converting enzyme (ACE), an enzyme primarily expressed in the pulmonary, renal, and endothelial tissues. This inhibition prevents the enzymatic proteolysis of the decapeptide angiotensin I into the biologically active octapeptide, angiotensin II, thereby modulating the renin-angiotensin-aldosterone system (RAAS).

The intracellular pathway is interrupted by a resultant decrease in circulating angiotensin II plasma concentration. This reduction leads to the disinhibition of the angiotensin II type 1 ( AT1) receptors on vascular smooth muscle, preventing the Gq protein-coupled receptor cascade that typically induces Ca^2+ mobilization and subsequent myocyte contraction. Furthermore, the diminished angiotensin II concentration decreases the stimulation of aldosterone secretion from the adrenal cortex. Aldosterone reduction leads to decreased expression of epithelial sodium channels and Na^+/ K^+-ATPase in the renal collecting ducts. Concurrently, Caprol's inhibition of kininase II (which is structurally identical to ACE) impedes the metabolism of the vasodilator peptide bradykinin, leading to a transient local increase. The system-level physiological consequence of this action is a net reduction in total peripheral vascular resistance and an accompanying decrease in intravascular volume and cardiac preload.

Dosage and Administration Information

How to Use Caprol

The usage of Caprol (Hydroxyprogesterone Caproate Injection) is highly procedural and is strictly governed by the official administration guidelines outlined in regulatory documents. The medicine is classified as an injectable therapy and is administered only by a healthcare provider; it is not intended for patient self-administration. Usage is structured around specific requirements for route, dosing, and duration, which define the official therapeutic protocol.


Official Administration Guidelines

Usage Constraint Requirement as per Official Labeling
Route & Form Administered exclusively as a deep intramuscular (IM) injection or, for specific formulations, a subcutaneous (SC) injection.
Standard Frequency Once weekly (every seven days) for the duration of the defined treatment course.
Dosing Range The dose for recurrent preterm birth risk reduction is 250 mg IM or 275 mg SC. Higher doses, such as 1,000 mg or more weekly, are used for other specified indications, such as advanced uterine adenocarcinoma.
Injection Technique The IM injection must be administered slowly—over one minute or longer—into the upper outer quadrant of the gluteus maximus due to the viscous nature of the solution.

Treatment Course and Timing

The timing of Caprol administration for the obstetrics indication is strictly time-window constrained. Treatment must be initiated between 16 weeks, 0 days and 20 weeks, 6 days of gestation and continued weekly until 37 weeks of gestation, or until delivery. If a scheduled dose is missed, it should be administered as soon as possible, and a new weekly schedule should be established from that date. The medicine is not indicated for patients under 16 years of age.

Recent Clinical Evidence

Research evidence / Overview of studies for Caprol

Evidence for Preventing Recurrent Preterm Birth

Caprol (hydroxyprogesterone caproate) was studied for use in pregnant women who have a history of having delivered a baby spontaneously before 37 weeks of gestation. The research primarily relies on Randomized Controlled Trials (RCTs), where women were assigned by chance to receive either Caprol or an inactive substance (placebo). These studies research examined whether receiving Caprol was associated with a lower rate of having another spontaneous preterm birth, and also studies monitored outcomes related to serious health issues in the newborns.

Initial research reported measured outcomes that were studied for differences compared to placebo. However, the largest and most recent study—a confirmatory, multinational RCT—reported how symptoms evolved in the observed populations but reported results that did not show a significant difference in the measured rate of recurrent preterm birth. This trial also did not report a significant change in the overall index of serious newborn health outcomes. The findings from these two major studies were mixed, creating complexity in the overall evidence landscape.

Consistency of Findings Across Major Trials

The scientific review of Caprol has largely centered on the inconsistency of findings between the initial research and the comprehensive follow-up research. When health authorities review medicines, they look for strong, consistent evidence, typically from more than one well-conducted study. Because the large, later trial did not confirm the findings from the earlier, smaller research, regulatory bodies have assessed that the evidence for effectiveness has not yet been established for this primary indication. This situation is an example of where evidence quality varies across studies, which contributes to the low certainty of the evidence.


Evidence for Other Gynecological and Fertility Indications

Caprol was studied for and received initial authorization in some regions for managing certain conditions associated with acute or disruptive episodes linked to insufficient progesterone. The evidence for these uses is mainly derived from older clinical trials and observational data. These older studies research examined outcomes related to functional imbalance, such as patterns related to changes in symptoms or achieving expected cycles. However, the evidence is limited and often comes from trials that had modest sample sizes or did not use contemporary comparative designs against other therapies.

Frequently Asked Questions (FAQ)

Common questions about Caprol (FAQ)


Q: Can Caprol be taken with other common medications like pain relievers?

A: Official regulatory documents specifically list certain medicines with known contraindications and major interactions, such as some HIV medications and blood thinners. Common over-the-counter pain relievers, like NSAIDs, are generally not listed as direct pharmacokinetic interaction partners in these documents. Regulatory bodies note the importance of consulting official product information when taking multiple medications.


Q: What happens if I stop taking Caprol suddenly?

A: Stopping a medication like Caprol suddenly may lead to an increase in the amount of gastric acid your body produces, even above the pre-treatment level. This effect is sometimes described as rebound acid hypersecretion in medical studies and official patient counseling information. Regulatory guidelines related to stopping medication generally defer to a healthcare professional's guidance.


Q: What research evidence supports the use of Caprol?

A: Regulatory documents state Caprol is indicated for conditions such as the short-term treatment and maintenance of healing of erosive esophagitis, and the long-term management of pathological hypersecretory conditions, including Zollinger-Ellison Syndrome. The evidence reviewed focuses on the drug's effect in suppressing gastric acid.


Q: Does Caprol affect birth control pills?

A: Clinical studies reviewed by regulatory agencies suggest that Caprol does not appear to significantly alter the levels of common ingredients in oral hormonal contraceptives, such as levonorgestrel and ethinylestradiol. This indicates a low likelihood of interaction for this specific use.


Q: Why is Caprol sometimes used for a different condition than its main purpose?

A: While the drug is primarily known for suppressing gastric acid, official regulatory labels specify multiple conditions for its authorized use. Beyond standard acid reflux issues, official documents list indications for Pathological Hypersecretory Conditions, which is a group of rare conditions involving excessive acid production, such as Zollinger-Ellison Syndrome.


Q: Why did my doctor prescribe Caprol instead of something else?

A: Regulatory information describes some key features of Caprol that distinguish it from similar medicines in its class. For example, official documents note that Caprol has a relatively low propensity for drug interactions related to the CYP450 enzyme system, which is a factor healthcare providers may consider for individuals taking multiple long-term medications.


Q: Is Caprol the same kind of medicine as [similar drug name]?

A: Caprol is classified as a Proton Pump Inhibitor (PPI), meaning it works by directly stopping the mechanism that produces acid in the stomach. While there are other classes of medicines, such as H2-receptor antagonists, that are used to treat similar acid-related symptoms, they operate using different physiological mechanisms.


Q: Is Caprol safe to use if I have kidney problems?

A: Official regulatory documents indicate that for most patients with renal impairment, no change to the standard dosage is typically required. However, the product information does document the potential for a rare, serious side effect called Acute Tubulointerstitial Nephritis (TIN), which is an inflammatory kidney condition.


Q: Does Caprol affect blood pressure or heart rate?

A: Caprol is not commonly listed as causing direct changes to blood pressure or heart rate in its adverse reaction profile. However, regulatory documents do report that Caprol can cause a lowering of magnesium levels (Hypomagnesemia) over time. Changes in magnesium levels have been associated with altered heart rhythms in clinical contexts.


Q: Does Caprol cause weight gain or weight loss?

A: Regulatory data, primarily from post-marketing surveillance, has included rare reports of both weight gain and weight loss in individuals using Caprol. Neither change is typically classified as a common or frequent side effect in the official product labeling.


Q: Does Caprol affect sleep or cause drowsiness?

A: Official regulatory labels list sleep disorders (such as insomnia) as an uncommon adverse reaction associated with Caprol. Additionally, patients may experience uncommon side effects like dizziness or vertigo, which could potentially affect alertness.


Q: Can I drink alcohol while taking Caprol?

A: While regulatory labels do not formally prohibit the consumption of alcohol while taking Caprol, official patient information often suggests that alcohol consumption may contribute to acid production in the stomach. This effect could potentially work against the medicine's goal of suppressing gastric acid.


Q: Is it possible to become dependent on Caprol?

A: The official product labeling does not use the term 'dependence.' However, studies discuss that when the medicine is stopped, a phenomenon called rebound acid hypersecretion can cause symptoms to quickly return. This effect may cause a patient to feel the need to resume the drug to relieve discomfort.


Q: Are there genetic factors that affect how someone responds to Caprol?

A: Yes, official regulatory documents note that genetic differences can influence how the body processes Caprol. The drug is metabolized by an enzyme called CYP2C19, and variations in the genes that control this enzyme can lead to differences in the concentration of Caprol that reaches the bloodstream.


Q: Can Caprol be crushed or split for easier taking?

A: Regulatory administration instructions state that the delayed-release tablets must not be split, chewed, or crushed. The tablet has a special enteric coating designed to protect the active ingredient from stomach acid. Damaging this coating may prevent the medicine from being absorbed as intended, potentially compromising its effect.


Q: What are the signs of an allergic reaction to Caprol?

A: Official regulatory documents describe signs that may indicate a serious allergic reaction, which include the appearance of a rash or hives, the onset of fever, swelling of the face, tongue, or throat, and the enlargement of lymph nodes. Such reactions, which are reported as rare, are considered serious and are listed in the official safety information.


Q: What is the maximum duration Caprol is typically recommended for?

A: The official labeling specifies that Caprol treatment for certain conditions, such as the healing of erosive esophagitis, is often a short-term course that lasts up to 8 weeks. However, the drug is also indicated for specific, more severe chronic conditions that may require long-term, controlled use.

How should Caprol be stored and disposed of?

How to Store and Dispose of Caprol?

The official instructions for Caprol (Pantoprazole) storage and disposal must be followed to ensure product stability and safety.

Storage Requirements

Caprol must be stored at Controlled Room Temperature (20 C to 25 C) and should be kept away from excess moisture and direct light. It is mandatory to keep all forms from freezing. Medication must remain in its original, tightly closed container and be stored out of the sight and reach of children.

Disposal Instructions

Do not flush Caprol down a toilet or drain. The preferred method for discarding unused or expired product is an official drug take-back program. If a take-back program is unavailable, the medicine should be mixed with an undesirable substance (e.g., dirt or coffee grounds) and sealed in a container before disposal in household trash.

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

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