acetaminophen/caffeine/pyrilamine

Action and Spectrum

Actions and Spectrum: 

Actions: 

acetaminophen is an OTC pain reliever and fever reducer. It inhibits the production of certain chemicals called prostaglandins in the brain involved in pain perception and body temperature regulation. caffeine acts on the central nervous system. It helps to increase alertness and reduce fatigue by blocking adenosine receptors in the brain, leading to increased wakefulness and improved focus. 

pyrilamine is an antihistamine that belongs to the class of first-generation antihistamines. It blocks the effects of histamine, a substance released during an allergic reaction that causes symptoms like sneezing, watery eyes, itching, and runny nose. 

Spectrum: 

The combination of acetaminophen, caffeine, and pyrilamine provides a broader spectrum of relief by targeting different aspects of pain, fever, and allergic symptoms. acetaminophen tackles pain and fever, caffeine helps with alertness and fatigue, and pyrilamine addresses allergy symptoms. However, it’s essential to use this medication as directed and consult a healthcare professional if you have any specific concerns or questions about its use and potential interactions with other medications. 

Drug Interaction

Adverse Reaction

Frequency Not Defined 

(acetaminophen) 

Urticaria 

Pruritic maculopapular rash 

Thrombocytopenia 

Leukopenia 

Laryngeal edema 

Angioedema 

Anaphylactoid reaction 

Agranulocytosis 

Hepatotoxicity 

Pancytopenia 

Neutropenia 

Thrombocytopenic purpura 

(caffeine) 

Insomnia 

Nervousness 

Restlessness 

Irritability 

Nausea 

Tremor 

Tinnitus 

Tachycardia 

Diuresis 

Vomiting 

Diarrhea 

Palpitations (dose dependent)  

(pyrilamine) 

Sedation 

Blurred vision 

Xerostomia 

Black Box Warning

Black Box Warning: 

None  

Contraindication / Caution

Contraindication/Caution: 

• Hypersensitivity 
• Liver disease 
• Alcohol consumption  
• Medical conditions 
• Drug interactions 
• CNS effects 
• Pregnancy  
• Breastfeeding 

Pregnancy / Lactation

Pregnancy consideration:  

Category C 

Breastfeeding warnings:  

The drug gets excreted in the breast milk. 

Pregnancy category: 

Category A: well-controlled and satisfactory studies show no risk to the fetus in the first or later trimester. 

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: No data is available for the drug under this category. 

Pharmacology

Pharmacology: 

acetaminophen, or paracetamol, is an analgesic (pain reliever) and antipyretic (fever reducer). It inhibits the production of prostaglandins, which transmit pain signals and regulate body temperature. acetaminophen primarily acts on the central nervous system to relieve pain and reduce fever. caffeine is a central nervous system stimulant. It works by blocking adenosine receptors, which leads to increased wakefulness, alertness, and reduced fatigue.

caffeine is often added to medications like acetaminophen to enhance their analgesic effects and counteract drowsiness. pyrilamine is a first-generation antihistamine. It blocks the effects of histamine, a substance released during an allergic reaction. By inhibiting histamine activity, pyrilamine helps to relieve symptoms of allergy like sneezing, itching, watery eyes, and runny nose. pyrilamine also has mild sedative effects, which can contribute to its use in treating insomnia or promoting relaxation. 

Pharmacodynamics: 

The combination of acetaminophen, caffeine, and pyrilamine in a single medication provides a multi-faceted pharmacodynamic profile. acetaminophen acts as an analgesic and antipyretic, caffeine is a stimulant and enhances analgesic effects, and pyrilamine is an antihistamine to alleviate allergy symptoms. 

It’s important to note that the pharmacodynamics of this combination medication can also be influenced by factors such as the dosage, individual patient characteristics, and potential interactions with other medications or substances.  

Pharmacokinetics: 

acetaminophen 

Absorption 

After oral administration, acetaminophen is rapidly and almost completely absorbed from the gastrointestinal tract. 

Distribution 

It has a moderate volume of distribution and is distributed throughout the body, including crossing the blood-brain barrier. 

Metabolism 

acetaminophen undergoes extensive hepatic metabolism primarily through conjugation with glucuronic acid and sulfate. The cytochrome P450 enzyme system metabolizes a small portion to a reactive intermediate detoxified by glutathione. 

Elimination and Excretion 

Most acetaminophen and its metabolites are excreted in the urine, with a small amount eliminated in the feces. The half-life is around 2 to 3 hours but can be longer in overdose cases or patients with impaired liver function. 

caffeine: 

Absorption 

caffeine is rapidly and completely absorbed after oral administration. Its absorption is not significantly affected by food. 

Distribution 

caffeine readily crosses the blood-brain barrier and is distributed throughout the body into various tissues and organs. 

Metabolism 

caffeine is extensively metabolized in the liver by cytochrome P450 enzymes, primarily CYP1A2. It undergoes N-demethylation to form three primary metabolites: paraxanthine, theobromine, and theophylline. 

Elimination and Excretion 

The elimination half-life of caffeine varies widely between individuals due to genetic and environmental factors. On average, it ranges from 3 to 5 hours. The majority of caffeine and its metabolites are excreted in the urine. 

pyrilamine: 

Absorption 

pyrilamine is rapidly absorbed after oral administration, with peak plasma concentrations reached within a few hours. 

Distribution 

pyrilamine is widely distributed throughout the body, including the central nervous system. 

Metabolism 

pyrilamine undergoes hepatic metabolism, primarily by N-demethylation, to form its major active metabolite, pyrilamine N-oxide. 

Elimination and Excretion 

The elimination half-life of pyrilamine is approximately 10 to 20 hours. The majority of the drug and its metabolites are excreted in the urine. 

Adminstartion

Administration: 

acetaminophen/caffeine/pyrilamine combination medication is typically available as tablet or capsule and is taken orally. The specific administration instructions may vary depending on the product and dosage strength. It’s important to carefully read and follow advisory on the medication label. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: acetaminophen/caffeine/pyrilamine 

Pronounced: a-seet-a-MIN-oh-fen, KAF-een, & peer-IL-a-meen 

Why do we use acetaminophen/caffeine/pyrilamine? 

acetaminophen, one of the components in this combination medication, is an effective analgesic (pain reliever) for mild to moderate pain. It can help alleviate various types of pain, including headaches, toothaches, muscle aches, menstrual cramps, and minor injuries. 

acetaminophen is also known for its antipyretic (fever-reducing) properties. It can help lower fever associated with common illnesses, such as colds, flu, and infections. 

caffeine, another component in the combination, acts as a stimulant and helps to increase alertness and reduce fatigue. It provides a temporary energy boost and enhances wakefulness. 

pyrilamine, an antihistamine, is included in the combination to relieve symptoms like sneezing, itching, watery eyes, and runny nose.