Percogesic

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Percogesic

Method of action: Analgesic

Treatment option:

Medically reviewed

Rosario Oropesa

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 Percogesic

Quick Facts

Property Description
Active Ingredient Acetaminophen and Diphenhydramine HCl
Form Oral Solid Dosage Forms (Tablet/Caplet)
Pharmacological Class Analgesic Combination; H1-Antihistamine
Common Use Pain relief accompanied by sleeplessness
Origin Synthetic

What Type of Medicine is Percogesic?

Percogesic is an aspirin-free, over-the-counter (OTC) drug classified pharmacologically as an analgesic combination medicine administered via the oral route. It is fundamentally a combination medicine specifically formulated with two distinct synthetic active ingredients, differentiating it from single-entity preparations. The product is typically presented as an oral solid dosage form, such as coated tablets or caplets, designed for simple ingestion. The combination of an analgesic and a sedating agent is intended to provide pain relief that facilitates rest.

Active Ingredients: Acetaminophen and Diphenhydramine

The medicine's composition is defined by the concurrent inclusion of Acetaminophen (a non-opioid analgesic and antipyretic agent, also known as APAP) and Diphenhydramine Hydrochloride (HCl). Acetaminophen works to reduce fever and address pain signals centrally through mechanisms involving the inhibition of prostaglandin synthesis. Diphenhydramine HCl belongs to the first-generation H1-antihistamine class, and its key function in this combination is due to its central nervous system activity, which imparts a sedative effect. This specific dual-ingredient composition is a distinctive feature of Percogesic, setting it apart from other APAP products that contain only the analgesic component.

General Purpose of the Dual-Action Formula

The overall purpose of this dual-action formula is to provide relief for mild to moderate pain symptoms while simultaneously leveraging the inherent sedative action of the Diphenhydramine component to promote rest. This combination is designed to manage discomfort, such as common aches and pains, when those symptoms are interfering with the ability to fall asleep or maintain sleep, offering a distinct approach compared to non-sedating pain relievers for night-time use.

Regulatory References

  1. DailyMed Drug Labeling
  2. NIH on Diphenhydramine Use

What side effects are possible with Percogesic?

Possible Side Effects and Safety Information

The official safety profile for Percogesic, a combination of Acetaminophen and Diphenhydramine HCl, is defined by regulatory documents that classify potential adverse reactions and constraints. The documented effects fall primarily into two categories: common CNS effects and rare, serious systemic risks.

Common and Expected Adverse Reactions

The majority of frequently documented adverse events are associated with the Diphenhydramine component, an H1-antihistamine. These effects are typically classified as common and involve the nervous system, potentially causing drowsiness, sleepiness, or dizziness. Other common reactions, linked to anticholinergic activity, include dry mouth, nose, or throat and sometimes stomach upset. The regulatory documents note that these CNS effects may be amplified when the medicine is used concurrently with other sedatives or alcohol.

Serious Adverse Reactions and Systemic Risks

The most critical safety concerns are associated with the Acetaminophen component and are required for prominent display in regulatory labeling. The serious reactions include the risk of Acute Liver Failure or Toxicity (hepatotoxicity), which is explicitly associated with exceeding the maximum recommended daily limit and cumulative exposure. Additionally, official documents report rare but life-threatening severe skin reactions (such as Stevens-Johnson Syndrome or Toxic Epidermal Necrolysis) linked to Acetaminophen.

Population-Specific Safety Notes

Specific safety considerations are documented for certain groups. Older adults are officially noted as being more susceptible to the central nervous system effects of Diphenhydramine, which can manifest as confusion or increased risk of falls. Use is also subject to restrictions in patients with conditions like glaucoma or specific chronic breathing problems, based on safety profiles documented by regulatory authorities.

Overdose and Emergency Response

The official regulatory profile for an overdose of this medicine, which contains Acetaminophen and Diphenhydramine HCl, is defined by a dual-agent toxicity risk. Overdose poses a serious and potentially life-threatening risk primarily due to the acetaminophen component, which can lead to severe liver damage, liver failure, and death. Initial overdose presentations may include non-specific symptoms such as nausea, vomiting, and abdominal pain. As toxicity progresses, regulatory sources document signs such as jaundice, severe skin reactions, seizures, or coma.

The diphenhydramine component may cause Central Nervous System (CNS) effects, including confusion, delirium, hallucinations, tremor, or potentially severe cardiovascular and respiratory depression. The official regulatory mandate establishes that immediate medical attention or contacting a Poison Control Center right away is critical for any suspected overdose, even if the person appears asymptomatic.

Prompt medical assessment is necessary for all ingestion scenarios. Management procedures include supportive and symptomatic care, along with mandated hospital monitoring. Treatment involves laboratory-guided administration of a specific antidote, N-acetylcysteine, to mitigate acetaminophen toxicity. Certain populations, such as those with chronic alcohol use or pre-existing liver disease, are noted in official labeling as having an increased risk for severe hepatotoxicity.

Therapeutic Uses of Percogesic

What Percogesic Treats: Main Uses and Benefits

The therapeutic domains are relevant for managing symptoms related to physical discomfort and pain-induced wakefulness. Its use is generally relevant when supportive symptom management is appropriate for temporary, acute episodes.


Pain Relief for Minor Aches and Discomfort

This medication is commonly used to help with a range of minor aches and pains, including headache, backache, muscular aches, discomfort associated with menstrual cramps or minor arthritis pain, and is also applied in addressing fever. This combination contributes to easing the overall symptom load during phases when symptoms become more noticeable, such as those accompanying a cold or the flu, and may help patients cope more steadily with symptom fluctuations.

Management of Pain-Induced Sleep Disruption

This is used across domains where additional symptomatic support is needed, particularly for managing symptoms that interfere with daily functioning. The product is generally used in situations where minor aches and discomfort may be contributing to difficulty falling asleep or staying asleep. Applied in settings that involve acute or unstable symptom patterns, the medication's dual action provides supportive relief. This assists with maintaining functional stability by supporting the patient during difficult episodes by easing distress and may assist with rest.

“The primary goal is to address the discomfort that may disrupt sleep, allowing for symptomatic relief and supporting general well-being.”

Quick Fact: Supports the patient during episodes of heightened discomfort and temporary difficulty sleeping.

Regulatory References

  1. DailyMed Drug Label on Percogesic

Eligibility and Restrictions for Use

Who Can and Cannot Use Percogesic?

The official eligibility profile for Percogesic (Acetaminophen and Diphenhydramine HCl) is defined by regulatory criteria that establish permitted, restricted, and prohibited use populations.

Populations for Whom Use Is Established

Percogesic is officially established for use by adults and children 12 years of age and older under standard labeled conditions.

Populations for Whom Use Is Prohibited (Contraindicated)

Individuals who must not use this medication include:

  • Children under 12 years of age (absolute age-based contraindication).
  • Patients with a known allergic reaction or hypersensitivity to acetaminophen, diphenhydramine, or any product ingredient.
  • Anyone currently taking any other product containing acetaminophen or diphenhydramine (including topical formulations).

Populations Requiring Professional Consultation

Use is restricted and requires consultation with a doctor or health professional if the patient has:

  • Liver disease (due to the acetaminophen component).
  • Glaucoma.
  • Breathing problems such as emphysema or chronic bronchitis.
  • Trouble urinating due to an enlarged prostate gland.
  • Individuals who consume three or more alcoholic drinks every day.
  • Pregnant or breast-feeding individuals.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory documentation structures the interaction profile of Percogesic (Acetaminophen and Diphenhydramine HCl) around strict prohibitions and the risk of additive effects.


Contraindicated Combinations and Substances

Co-administration is strictly prohibited with any other product containing Acetaminophen due to the officially documented risk of severe liver damage, or with any product containing Diphenhydramine due to the risk of increased systemic side effects. The product is also formally contraindicated with Monoamine Oxidase Inhibitors (MAOIs), a restriction that includes a mandatory 14-day separation period following the discontinuation of MAOI therapy.


Pharmacodynamic and Substance Interactions

Category Documented Interaction Risk
Alcoholic Beverages, Sedatives, or Tranquilizers May cause marked drowsiness due to documented additive central nervous system (CNS) depressant effects.
Alcoholic Beverages Increases the official risk of severe liver damage associated with the acetaminophen component. This risk is specifically noted for individuals consuming three or more alcoholic drinks daily.
Warfarin (Anticoagulant) Co-administration is officially listed as requiring consultation due to potential effects on blood clotting.

This framework emphasizes risk management through avoidance rules and highlights interactions that result in heightened toxicity or compounded CNS effects, based solely on governmental labeling.

Mechanism of Action

How Percogesic Works

Percogesic utilizes a dual-component mechanism of action by engaging distinct central and peripheral pathways to modify relevant biochemical signaling. The drug's two active ingredients target enzyme-mediated signaling and neurotransmitter receptor systems, resulting in predictable physiological adjustments.


Modulation of Prostaglandin Signaling

This mechanistic domain covers the action of acetaminophen, which works within the central nervous system. It is believed to inhibit specific cyclooxygenase (COX) enzyme pathways, thereby reducing the synthesis of prostaglandins. This modification of an early molecular step in inflammatory cascades alters activity within processes regulating nociception and thermoregulation.


Regulation of Histamine and Acetylcholine Systems

This domain involves the action of diphenhydramine, which primarily acts as an inverse agonist at the H1 histamine receptor and an antagonist at muscarinic acetylcholine receptors. By engaging these receptor-mediated signaling pathways, it decreases the downstream effect of specific mediators in the central nervous system. This engagement modulates the overall activity within the targeted pathways, resulting in downstream effects such as reduced alertness and altered afferent signaling.

Dosage and Administration Information

How to Use Percogesic: Administration Guidelines

The usage of Percogesic is defined by specific administration principles, focusing on the approved dosage forms, frequency, and maximum daily limits. The product is primarily intended for short-term, as-needed (PRN) administration.


Administration Scope

The method of introducing the medicine into the body is the oral route, utilizing the available solid dosage forms.

Instruction Original Strength (325 mg/ 12.5 mg) Extra Strength (500 mg/ 12.5 mg)
Standard Unit Dose 2 tablets per dose 2 caplets per dose
Frequency Pattern Every 4 to 6 hours Every 6 hours
Maximum Dose Do not exceed 8 tablets in 24 hours Do not exceed 6 caplets in 24 hours

Procedural Constraints

A critical procedural constraint is adhering to the maximum recommended dosage. The protocol involves calculating the total intake of Acetaminophen from all concurrent sources, which should not exceed 4,000 mg in any 24-hour period. The use of Percogesic is intended for individuals aged 12 years and older; for children under this age, label instructions require consultation with a doctor prior to administration.


Connection to the Overall Use Protocol

These instructions establish a structured administration protocol with defined time-based intervals and unit quantity limits. The protocol ensures that the use remains intermittent and short-term, preventing unintentional overexposure to the active ingredients by setting clear boundaries on the total amount permitted within a 24-hour cycle.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Percogesic


Evidence for Use in Contexts Where Pain is Associated with Occasional Sleeplessness

Research examining this product's primary dual-use relies on a large collection of studies related to its individual active components. The regulatory status of this combination is supported by its classification as Generally Recognized as Safe and Effective (GRASE), based on an extensive body of public literature, including Randomized Controlled Trials (RCTs) and Systematic Reviews that establish the individual components' regulatory classifications: Acetaminophen as an analgesic and Diphenhydramine as a short-term sleep aid. These studies were conducted during periods of increased symptom activity and research explored short-term changes in patient-reported outcomes describing perceived discomfort and sleep. The cumulative research reviewed includes studies examining patient-reported experiences related to physical discomfort and time to fall asleep.


Evidence for Relief of Minor Aches, Pains, and Fever

The research base for the Acetaminophen component is derived from an extensive history of use and numerous high-quality Randomized Controlled Trials and Meta-Analyses. This research was evaluated in studies examining patient experiences with various mild to moderate acute pain types. Trials and studies monitored outcomes related to pain intensity scores and body temperature. The data collected provides a consistent framework used by regulatory bodies for its classification as a treatment for minor aches, pains, and fever. It is important to note that the findings from these studies relate specifically to the Acetaminophen component when used alone.


Research Gaps and Follow-up Duration

Research highlights what is known—and what is still uncertain—about this combination product. The key clinical studies supporting the dual indication primarily included the general adult population and children 12 years and older. The follow-up durations were limited in most regulatory research, with an intense focus on acute, occasional symptoms. Limited information for long-term outcomes is available, and research has not established its role in chronic conditions. Furthermore, comparative evidence is lacking to definitively describe the research structure of the combination over using the analgesic component alone.

Key Studies & References

  1. Percogesic Tablets Drug Labeling (NDC 52997-401)
  2. DailyMed Drug Labeling: Acetaminophen and Diphenhydramine Combination
  3. Diphenhydramine Use Information (MedlinePlus)

Frequently Asked Questions (FAQ)

Common questions about Percogesic (FAQ)

Q: Is Percogesic classified as an NSAID?

Percogesic is classified as an analgesic combination medicine. Official information indicates that one of its active ingredients, acetaminophen, is a non-opioid analgesic and antipyretic agent. Acetaminophen is not categorized as a non-steroidal anti-inflammatory drug (NSAID).


Q: What kind of pain is Percogesic typically indicated for, such as muscle aches or menstrual cramps?

Regulatory documents state that the product is intended for the temporary relief of minor aches and pains. This generally includes common symptoms such as headache, toothache, muscular aches, backache, and menstrual cramps. The product is described as designed to manage these discomforts when they are associated with occasional sleeplessness.


Q: Does Percogesic come in different available formulations, such as liquid, caplets, or gelcaps?

The official product labeling identifies the available physical forms as oral solid dosage forms, specifically tablets and caplets. The current regulatory documentation for the drug does not list other forms, such as liquid or gelcaps.


Q: What are the common signs of an allergic reaction to Percogesic, as described in official documents?

The official labeling describes that hypersensitivity reactions can occur with this medication. Documented signs listed in the regulatory information include common reactions like itching, rash, or hives. More severe signs can involve difficulty breathing or swelling of the throat, tongue, or face.


Q: Can Percogesic cause side effects like dry mouth, constipation, or blurred vision?

Regulatory documents report dry mouth, blurred vision, and dizziness as possible adverse reactions due to the diphenhydramine component. While dry mouth is commonly noted, constipation is not typically listed as a frequent side effect in the primary official labeling.


Q: Is there an official warning about operating heavy machinery or driving after taking Percogesic?

Yes, the official labeling contains a precaution related to the potential for the medicine to cause drowsiness or dizziness. This precaution states that caution should be used when driving a motor vehicle or operating heavy machinery.


Q: Can Percogesic cause stomach upset, nausea, or vomiting?

Stomach upset is listed in the official documents as a common adverse reaction. Nausea and vomiting are also noted as potential side effects. These reactions are sometimes associated with the acetaminophen component of the medication.


Q: How long do the therapeutic effects of Percogesic usually last in the body?

The duration of the product’s therapeutic effect is supported by the recommended dosing interval. The recommended dosing interval cited in the official directions is every 4 to 6 hours (or every 6 hours for Extra Strength). This range suggests the typical period of relief sought before another dose may be taken.


Q: Is there a recommended maximum length of time for continuous use of Percogesic?

Official guidance defines the intended short-term nature of use by setting a time limit. The official labeling requires that use be stopped, and a healthcare professional consulted, if pain persists for more than 10 days or if fever persists for more than 3 days.


Q: Can Percogesic be used to treat symptoms of a common cold or flu?

The official indication for Percogesic is the temporary relief of minor aches, pains, and fever, particularly when these symptoms are associated with sleeplessness. These symptoms are commonly experienced during a cold or flu. The product is not specifically indicated for treating the cold or flu virus itself.


Q: Is it possible to develop a physical dependency on Percogesic?

Official classification notes that the active ingredients are a non-opioid analgesic and an H1-antihistamine. Products containing these components do not typically carry addiction, dependence, or abuse warnings in regulatory labeling, unlike controlled substances.


Q: Does Percogesic interact with common dietary supplements or caffeine consumption?

The official interaction section explicitly lists severe warnings for substances like alcohol and MAOIs. Dietary supplements and caffeine are generally not listed in the primary product labeling, indicating that no official warning for these is typically present.


Q: Can Percogesic be taken alongside common blood pressure medications? (Informational)

The official labeling does not generally list specific blood pressure medications in its interaction warnings. The labeling states that a professional should be consulted prior to use, particularly regarding all concurrent conditions and medications, including any blood pressure treatments.


Q: Does Percogesic affect the results of any laboratory blood tests?

Official labeling notes that the acetaminophen component may interfere with the results of certain laboratory tests. This interference includes potentially causing falsely decreased values for blood glucose and affecting tests that measure specific metabolic compounds.


Q: Can people with pre-existing kidney conditions or disease use Percogesic?

The official labeling explicitly cites liver disease as a key warning that requires professional consultation prior to use. Regulatory guidance requires consultation with a healthcare professional before taking the medicine if an individual has any underlying medical condition, including kidney concerns.


Q: Does Percogesic cause rebound headaches if used frequently?

The official labeling includes a caution related to medication overuse. It specifically warns that headaches may worsen or recur if the product is used for pain relief for a duration longer than 10 days (or as directed). This is a documented caution related to frequent or prolonged use.

How should Percogesic be stored and disposed of?

Official Storage Requirements

Percogesic tablets must be stored at controlled room temperature, specifically between 15°C and 30°C (59°F and 86°F), as documented in the drug labeling. To maintain product stability, it is mandatory to avoid excessive heat, light, and moisture. The medicine must remain in its original container and be kept tightly closed when not in use. Importantly, all medication must be stored out of the sight and reach of children.

Official Disposal Instructions

Unused or expired Percogesic should be disposed of through an authorized drug take-back program whenever possible. If a take-back option is unavailable, the product must be prepared for disposal in the household trash: the medicine should be mixed with an unappealing substance, such as dirt or used coffee grounds, sealed in a bag or container, and then discarded. Flushing the tablets down the toilet or sink is strictly prohibited according to government guidance for this non-flush list medicine.

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

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