Trimeprazine with Prednisolone
Trimeprazine tartrate and prednisolone
Also known as: Temaril-P · Vanectyl-P · Alimemazine tartrate · Chemists Own Peetalix · Nedeltran · Panectyl · Repeltin · Theralene · Vallergan · Variargil
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Antipruritic and antitussive therapy | Weight up to 10 lb = 1/2 tab PO twice daily; 11-20 lb = 1 tablet twice daily; 21-40 lb = 2 tablets twice daily; over 40 lb = 3 tablets twice daily. After 4 days reduce dose to 1/2 of initial dose or to an amount just sufficient to maintain remission of symptoms; adjust as necessary. | PO | twice daily | After 4 days reduce dose | 🌎 NA |
| Treatment of pruritus | 1 tablet per 10 kg of body weight once daily for 3-5 days, then every other day. | PO | once daily then every other day | 3-5 days then every other day | 🌎 NA |
| Atopic dermatitis | 1 tablet of Temaril-P per 5 kg body weight q12h for one week, then once daily for one week, then q48h (every other day). | PO | q12h then once daily then q48h | 1 week q12h, 1 week once daily, then q48h | 🌎 NA |
- Treatment of pruritus: Giving with an EFA (essential fatty acid) may reduce the dose and frequency, if not the need for, glucocorticoids.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Trimeprazine with Prednisolone (commonly known by the brand name Temaril-P®) is a combination medication widely used in veterinary medicine primarily to manage pruritus (itching) and coughing in dogs.
- Trimeprazine (also known as alimemazine) is a phenothiazine derivative that acts as a potent antihistamine, mild sedative, and antitussive.
- Prednisolone is an intermediate-acting glucocorticoid that provides robust anti-inflammatory and immunosuppressive effects.
Clinical Pearl: The synergistic effect of combining an antihistamine with a corticosteroid allows for a lower dose of prednisolone to achieve the same antipruritic effect. This "steroid-sparing" approach helps minimize the risk of long-term glucocorticoid-induced adverse effects while effectively controlling clinical signs.
Mechanism of action
The drug exerts its effects through two distinct mechanisms:
- Trimeprazine: Acts primarily as a competitive antagonist at H1-histamine receptors, preventing histamine-induced capillary permeability, vasodilation, and pruritus. It also exhibits central antitussive and sedative properties by antagonizing central dopamine (D2) and muscarinic (M1) receptors in the brainstem and reticular activating system.
- Prednisolone: Diffuses across cell membranes and binds to cytosolic glucocorticoid receptors. The receptor-ligand complex translocates to the nucleus → alters gene transcription → induces production of lipocortin-1 (annexin-1) → inhibits phospholipase A2. This blocks the release of arachidonic acid, thereby suppressing the synthesis of key inflammatory mediators, including prostaglandins and leukotrienes.
Safety & warnings
Contraindications
- Systemic fungal infections
- Hypovolemia or shock
- Tetanus or strychnine intoxication
- Late pregnancy (last trimester) due to risk of inducing parturition
Adverse effects
- Sedation
- Depression
- Hypotension
- Extrapyramidal reactions (rigidity, tremors, weakness, restlessness)
- Polyuria (increased urination)
- Polydipsia (increased thirst)
- Polyphagia (increased appetite)
- Elevated liver enzymes
- Weight loss or weight gain
- Vomiting
- Diarrhea
- Iatrogenic hyperadrenocorticism (Cushing's syndrome) with chronic use
- Delayed wound healing
- Osteoporosis
- Increased susceptibility to infections
Precautions
Use with caution in patients with hepatic dysfunction, cardiac disease, active bacterial or viral infections, peptic ulcers, acute psychoses, corneal ulcers, Cushingoid syndrome, diabetes, osteoporosis, predisposition to thrombophlebitis, hypertension, congestive heart failure (CHF), renal insufficiency, general debilitation, and in very young animals. If used chronically, therapy must be withdrawn gradually to prevent Addisonian crisis. May alter thyroid testing and skin allergy testing.
Drug interactions
Phenothiazines may increase hypotensive effects
Concomitant use with glucocorticoids may cause severe hypokalemia
May cause reduced GI absorption of oral phenothiazines
May cause reduced GI absorption of oral phenothiazines
In myasthenia gravis patients, concomitant use may lead to profound muscle weakness
Glucocorticoids may reduce salicylate blood levels
Increased risk for cardiac arrhythmias when used with phenothiazines
May cause additive CNS depression
Glucocorticoids may inhibit hepatic metabolism of cyclophosphamide
May mutually inhibit hepatic metabolism, increasing blood levels of both drugs
Increased risk for arrhythmias secondary to glucocorticoid-induced hypokalemia
Concomitant use with glucocorticoids may cause hypokalemia
May increase metabolism of glucocorticoids
May potentiate the effects of glucocorticoids
Insulin requirements may increase due to glucocorticoid-induced hyperglycemia
May decrease metabolism of glucocorticoids
May alter steroid metabolism; higher steroid doses may be needed
Increased risk of gastrointestinal ulceration
Virus replication may be augmented; diminished immune response may occur
May increase phenothiazine plasma levels
May increase the metabolism of glucocorticoids
May increase the metabolism of glucocorticoids
May increase the metabolism of glucocorticoids
Monitoring
- Efficacy (reduction in pruritus or coughing)
- Degree of sedation
- Anticholinergic effects
- Adverse effects associated with corticosteroids (e.g., PU/PD, weight changes, liver enzyme elevations)
Overdose
Acute overdosage should be handled similarly to phenothiazine (e.g., acepromazine) toxicity. Overdose may cause profound sedation, depression, hypotension, and extrapyramidal signs (tremors, rigidity). Treatment is largely supportive and symptomatic. Do not use epinephrine for hypotension as it may cause further vasodilation (epinephrine reversal); use norepinephrine or phenylephrine if pressors are required.
Available products
Formulations
- Tablets
Veterinary
- Trimeprazine Tartrate 5 mg / Prednisolone 2 mg Tablets (Temaril-P®, Vanectyl-P®)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store trimeprazine products at room temperature (15-30°C); protect tablets from light.
Client information
- Increased Thirst and Urination: Your dog will likely drink more water and need to urinate more frequently. Ensure they have constant access to fresh water and provide extra bathroom breaks.
- Increased Appetite: This medication can make your dog very hungry. Stick to their normal feeding schedule to prevent unwanted weight gain.
- Sedation: You may notice mild drowsiness or lethargy, especially during the first few days of treatment. This is normal but contact your vet if it seems severe.
- Do Not Stop Abruptly: If your dog has been on this medication for more than a few weeks, the dose must be tapered slowly under veterinary guidance. Stopping suddenly can cause a life-threatening hormonal imbalance.
- Monitor for Infections: Because this drug suppresses the immune system, contact your veterinarian if you notice signs of infection, worsening skin lesions, or severe lethargy.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.