Trimeprazine is a medication primarily used in veterinary medicine. It belongs to a class of drugs known as phenothiazine derivatives, which have various effects including sedation, antiemetic (preventing vomiting), and antihistaminic properties (reducing allergic reactions). In veterinary practice, trimeprazine is often used as an antihistamine to alleviate itching and allergic reactions in dogs and cats, and it may also be used as a sedative for calming anxious or agitated animals.
Alimemazine (Trimeprazine) is a Phenothiazine derivative that has enhanced antipruritic and antihistaminic effects with reduced central effects.
It is used in the symptomatic treatment of cough and pruritis.
Trimeprazine Dose in Adults
Alimemazine dose in the treatment of Cough and pruritus:
- When starting, it's best to begin with a small amount and adjust as needed.
- For oral use, typically it's given as 2.5 mg to 5 mg twice a day after meals, and another 5 mg at bedtime.
- Or, it could be given as 5 mg to 10 mg just once at bedtime.
- In severe cases of itching, for pets in the hospital, doses up to 80 mg a day, spread throughout the day, may be considered under close supervision.
Trimeprazine Dose in Children
Trimeprazine Dose in the treatment of Cough and pruritus:
Note: When starting, it's best to begin with a small amount and adjust as needed.
For children aged 2 to 12 years:
- The usual starting dose is 2.5 mg to 5 mg once a day at bedtime.
- If necessary, an extra dose of 2.5 mg can be given twice daily after meals.
- The maximum dose for children is 15 mg per day.
Adolescents:
- Adolescents should follow the dosing for adults.
Pregnancy Risk factor: C
- Animal studies have not shown any negative effects on pregnancy or reproduction.
Trimeprazine use during breastfeeding:
- Phenothiazines, a group of drugs that includes trimeprazine, can be passed into human breast milk, but we're not sure if trimeprazine specifically does this.
Trimeprazine Dose in Renal Disease:
- The manufacturer's instructions do not include any specific changes to the dosage for people with kidney problems.
Trimeprazine Dose in Liver Disease:
- The manufacturer's instructions do not mention any changes to the dosage for individuals with liver problems.
Side effects of Alimemazine (Trimeprazine):
- Cardiovascular:
- Cardiac Arrhythmia
- ECG Changes
- Syncope
- Torsades De Pointes
- Central Nervous System:
- Akathisia
- Depression
- Drowsiness (Dose Related)
- Dystonia
- Mood Elevation
- Nightmares
- Parkinsonian-Like Syndrome
- Seizure
- Tardive Dyskinesia
- Gastrointestinal:
- Abdominal Distress
- Gastric Distress
- Nausea
- Xerostomia
- Hepatic:
- Cholestatic Jaundice
- Neuromuscular & Skeletal:
- Dyskinesia (Transient)
- Neuromuscular Reaction
- Respiratory:
- Nasal Congestion
Contraindication to Trimeprazine Include:
- Trimeprazine should not be used if there's a history of severe allergic reactions to trimeprazine itself, any of its ingredients, or other drugs in the phenothiazine family.
- It's also not suitable if there's a history of blood disorders linked to trimeprazine or other phenothiazines, or if there's a state of central nervous system depression caused by barbiturates, alcohol, opioids, or painkillers.
- Additionally, it's not recommended for children under 2 years of age.
Warnings and precautions
Modified cardiac conduction
- Trimeprazine can affect the way the heart beats by changing its conduction.
- This might show up on an ECG (electrocardiogram) as changes in the QT interval, ST depression, or alterations in T or U waves.
- In some cases, it can lead to serious heart rhythm problems like atrioventricular (AV) block, supraventricular tachycardia, ventricular tachycardia, and fibrillation.
- This risk may be higher in elderly patients, those with heart disease, low potassium levels, or those taking tricyclic antidepressants at the same time.
- Rarely, it can lead to severe heart rhythm disturbances like torsades de pointes, ventricular fibrillation, cardiac arrest, and sudden death.
CNS depression:
- Trimeprazine can lead to central nervous system (CNS) depression, potentially affecting both physical and mental abilities.
- Patients should be warned about activities requiring mental alertness, such as operating machinery or driving, while taking this medication.
- Drowsiness is a common side effect, but it may lessen within 1 to 3 weeks.
- However, elderly individuals and those taking doses equal to or greater than 30 mg per day might experience drowsiness more frequently.
- Starting treatment with a lower dose and gradually increasing it can help minimize drowsiness.
Extrapyramidal effects:
- Trimeprazine can lead to extrapyramidal symptoms, affecting movements and muscle control, such as tremors, muscle stiffness, painful muscle contractions, abnormal muscle movements (dystonia), restlessness (akathisia), and tardive dyskinesia.
- These effects may be related to the dose or how long the medication is taken.
- Acute reactions might occur within 4 days in children and young adults, while symptoms like Parkinsonism could develop weeks or months after starting treatment in adults and the elderly.
- If neuromuscular reactions occur, the medication should be stopped immediately, especially in children or pregnant women, with no restart.
- For other patients, restarting therapy may be considered at a lower dose.
Hepatic impairment
- Trimeprazine should be used cautiously in patients with liver problems or jaundice.
Seizures:
- Trimeprazine should be used cautiously in patients who are at risk of seizures, such as those with a history of seizures or seriously ill or dehydrated children.
Trimeprazine (alimemazine): Drug Interaction
|
Risk Factor C (Monitor therapy) |
|
|
Acetylcholinesterase Inhibitors |
May diminish the therapeutic effect of Anticholinergic Agents. Anticholinergic Agents may diminish the therapeutic effect of Acetylcholinesterase Inhibitors. |
|
Alcohol (Ethyl) |
Alcohol's CNS depressing impact may be amplified by CNS depressants (Ethyl). |
|
Alizapride |
CNS depressants may have an enhanced CNS depressant impact. |
|
Amantadine |
may strengthen an anticholinergic agent's anticholinergic action. |
|
Amezinium |
Antihistamines may intensify Amezinium's stimulant effects. |
|
Amphetamines |
may lessen antihistamines' sedative effects. |
|
Anticholinergic Agents |
Other anticholinergic agents' negative or hazardous effects could be amplified. |
|
ARIPiprazole |
ARIPiprazole's serum levels may rise in response to trimeprazine. |
|
Betahistine |
Antihistamines may diminish the therapeutic effect of Betahistine. |
|
Botulinum Toxin-Containing Products |
May enhance the anticholinergic effect of Anticholinergic Agents. |
|
Brexanolone |
CNS Depressants may enhance the CNS depressant effect of Brexanolone. |
|
Brimonidine (Topical) |
May enhance the CNS depressant effect of CNS Depressants. |
|
Bromopride |
May enhance the CNS depressant effect of CNS Depressants. |
|
Cannabidiol |
May enhance the CNS depressant effect of CNS Depressants. |
|
Cannabis |
May enhance the CNS depressant effect of CNS Depressants. |
|
Chloral Betaine |
May enhance the adverse/toxic effect of Anticholinergic Agents. |
|
Chlorphenesin Carbamate |
May enhance the adverse/toxic effect of CNS Depressants. |
|
CNS Depressants |
Trimeprazine may enhance the CNS depressant effect of CNS Depressants. |
|
Dimethindene (Topical) |
May enhance the CNS depressant effect of CNS Depressants. |
|
Doxylamine |
May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended. |
|
Dronabinol |
May enhance the CNS depressant effect of CNS Depressants. |
|
Esketamine |
May enhance the CNS depressant effect of CNS Depressants. |
|
Gastrointestinal Agents (Prokinetic) |
Anticholinergic Agents may diminish the therapeutic effect of Gastrointestinal Agents (Prokinetic). |
|
Glucagon |
Anticholinergic Agents may enhance the adverse/toxic effect of Glucagon. Specifically, the risk of gastrointestinal adverse effects may be increased. |
|
HydrOXYzine |
May enhance the CNS depressant effect of CNS Depressants. |
|
Itopride |
Anticholinergic Agents may diminish the therapeutic effect of Itopride. |
|
Kava Kava |
May enhance the adverse/toxic effect of CNS Depressants. |
|
Lofexidine |
May enhance the CNS depressant effect of CNS Depressants. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. |
|
Magnesium Sulfate |
May enhance the CNS depressant effect of CNS Depressants. |
|
MetyroSINE |
CNS Depressants may enhance the sedative effect of MetyroSINE. |
|
Mianserin |
May enhance the anticholinergic effect of Anticholinergic Agents. |
|
Minocycline |
May enhance the CNS depressant effect of CNS Depressants. |
|
Mirabegron |
Anticholinergic Agents may enhance the adverse/toxic effect of Mirabegron. |
|
Mirtazapine |
CNS Depressants may enhance the CNS depressant effect of Mirtazapine. |
|
Nabilone |
May enhance the CNS depressant effect of CNS Depressants. |
|
Nitroglycerin |
Anticholinergic Agents may decrease the absorption of Nitroglycerin. Specifically, anticholinergic agents may decrease the dissolution of sublingual nitroglycerin tablets, possibly impairing or slowing nitroglycerin absorption. |
|
Piribedil |
CNS Depressants may enhance the CNS depressant effect of Piribedil. |
|
Pramipexole |
CNS Depressants may enhance the sedative effect of Pramipexole. |
|
Ramosetron |
Anticholinergic Agents may enhance the constipating effect of Ramosetron. |
|
ROPINIRole |
CNS Depressants may enhance the sedative effect of ROPINIRole. |
|
Rotigotine |
CNS Depressants may enhance the sedative effect of Rotigotine. |
|
Rufinamide |
May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. |
|
Selective Serotonin Reuptake Inhibitors |
CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. |
|
Tetrahydrocannabinol |
May enhance the CNS depressant effect of CNS Depressants. |
|
Tetrahydrocannabinol and Cannabidiol |
May enhance the CNS depressant effect of CNS Depressants. |
|
Thiazide and Thiazide-Like Diuretics |
Anticholinergic Agents may increase the serum concentration of Thiazide and Thiazide-Like Diuretics. |
|
Topiramate |
Anticholinergic Agents may enhance the adverse/toxic effect of Topiramate. |
|
Risk Factor D (Consider therapy modification) |
|
|
Benzylpenicilloyl Polylysine |
Antihistamines may diminish the diagnostic effect of Benzylpenicilloyl Polylysine. Management: Suspend systemic H1 antagonists for benzylpenicilloyl-polylysine skin testing and delay testing until systemic antihistaminic effects have dissipated. A histamine skin test may be used to assess persistent antihistaminic effects. |
|
Blonanserin |
CNS Depressants may enhance the CNS depressant effect of Blonanserin. |
|
Buprenorphine |
|
|
Chlormethiazole |
May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. |
|
Droperidol |
May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Exceptions to this monograph are discussed in further detail in separate drug interaction monographs. |
|
Flunitrazepam |
CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. |
|
Hyaluronidase |
Antihistamines may diminish the therapeutic effect of Hyaluronidase. Management: Patients receiving antihistamines (particularly at larger doses) may not experience the desired clinical response to standard doses of hyaluronidase. Larger doses of hyaluronidase may be required. |
|
HYDROcodone |
CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Avoid concomitant use of hydrocodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. |
|
Methotrimeprazine |
CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. |
|
Opioid Agonists |
CNS Depressants may enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. |
|
OxyCODONE |
CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. |
|
Perampanel |
May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. |
|
Pramlintide |
May enhance the anticholinergic effect of Anticholinergic Agents. These effects are specific to the GI tract. |
|
Secretin |
Anticholinergic Agents may diminish the therapeutic effect of Secretin. Management: Avoid concomitant use of anticholinergic agents and secretin. Discontinue anticholinergic agents at least 5 half-lives prior to administration of secretin. |
|
Sodium Oxybate |
May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated. |
|
Suvorexant |
CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. |
|
Tapentadol |
May enhance the CNS depressant effect of CNS Depressants. Management: Avoid concomitant use of tapentadol and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. |
|
Zolpidem |
CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. |
|
Risk Factor X (Avoid combination) |
|
|
Aclidinium |
May enhance the anticholinergic effect of Anticholinergic Agents. |
|
Azelastine (Nasal) |
CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). |
|
Bromperidol |
May enhance the CNS depressant effect of CNS Depressants. |
|
Cimetropium |
Anticholinergic Agents may enhance the anticholinergic effect of Cimetropium. |
|
Eluxadoline |
Anticholinergic Agents may enhance the constipating effect of Eluxadoline. |
|
Glycopyrrolate (Oral Inhalation) |
Anticholinergic Agents may enhance the anticholinergic effect of Glycopyrrolate (Oral Inhalation). |
|
Glycopyrronium (Topical) |
May enhance the anticholinergic effect of Anticholinergic Agents. |
|
Ipratropium (Oral Inhalation) |
May enhance the anticholinergic effect of Anticholinergic Agents. |
|
Levosulpiride |
Anticholinergic Agents may diminish the therapeutic effect of Levosulpiride. |
|
Orphenadrine |
CNS Depressants may enhance the CNS depressant effect of Orphenadrine. |
|
Oxatomide |
May enhance the anticholinergic effect of Anticholinergic Agents. |
|
Oxomemazine |
May enhance the CNS depressant effect of CNS Depressants. |
|
Paraldehyde |
CNS Depressants may enhance the CNS depressant effect of Paraldehyde. |
|
Pitolisant |
Antihistamines may diminish the therapeutic effect of Pitolisant. |
|
Potassium Chloride |
Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Chloride. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium chloride. |
|
Potassium Citrate |
Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Citrate. |
|
Revefenacin |
Anticholinergic Agents may enhance the anticholinergic effect of Revefenacin. |
|
Thalidomide |
CNS Depressants may enhance the CNS depressant effect of Thalidomide. |
|
Tiotropium |
Anticholinergic Agents may enhance the anticholinergic effect of Tiotropium. |
|
Umeclidinium |
May enhance the anticholinergic effect of Anticholinergic Agents. |
Monitor:
Monitoring Mental Status and Vital Signs
- Keep an eye on mental alertness and behavior.
- Check vital signs like heart rate, blood pressure, and temperature as needed, especially if there are concerns about the patient's health.
How to administer Alimemazine (Trimeprazine, Penectyl)?
Taking Trimeprazine Orally
- Trimeprazine can be taken with or without food.
- Taking it after meals might help decrease the chance of side effects.
Mechanism of action of Alimemazine (Trimeprazine, Panectyl):
- Trimeprazine is a type of phenothiazine derivative.
- It has fewer effects on the central nervous system compared to other drugs in this class.
- It's particularly effective at relieving itching and allergic reactions.
- Trimeprazine also works well as a sedative, antiemetic (reduces vomiting), antispasmodic (reduces muscle spasms), and against serotonin-related issues.
- Its impact on the autonomic nervous system is relatively low.
Absorption:
- Trimeprazine absorption is slowed down when taken with food.
Distribution:
- More than 90% of trimeprazine binds to plasma proteins.
Bioavailability:
- When taken in tablet form, less than 70% of trimeprazine is absorbed into the body.
Half-life, elimination:
- Trimeprazine has an elimination half-life of about 4.78 hours, indicating how long it takes for half of the drug to leave the body.
Time to peak serum concentration:
- For tablets, it takes around 4.5 hours for trimeprazine to reach its highest concentration in the bloodstream after being taken.
International Brands of Trimeprazine:
- Panectyl
Trimeprazine Brands in Pakistan":
No Brands Available in Pakistan.
