哌嗪
哌嗪是一種窄效驅蟲藥，主要用於治療狗、貓、馬、豬和家禽的**蛔蟲**感染。 * 在患有胃腸炎或懷孕的動物中使用被認為是安全的。 * **臨床提示**：由於哌嗪僅對成蟲有效，且對鉤蟲、鞭蟲或絛蟲無效，隨著新型廣效驅蟲藥（如雙羥萘酸噻嘧啶、芬苯達唑和大環內酯類）的出現，其在現代獸醫學中的使用已大幅減少。 * 市面上有各種鹽類形式（檸檬酸鹽、己二酸鹽、磷酸鹽、六水合物、二鹽酸鹽），其中含有不同量的哌嗪活性基質。
作用機制: Piperazine exerts a **'curare-like' effect** on susceptible nematodes. * It acts as a **GABA receptor agonist** and blocks **acetylcholine** at the myoneural junction of the parasite. * This causes **flaccid paralysis** (narcotizing the worm), allowing the live, paralyzed worms to be passed out of the host's gastrointestinal tract with the feces. * In ascarids, it also inhibits succinic acid production.
各物種劑量
- Treatment of ascarids · 45-65 mg of base/kg PO; 150 mg maximum · PO · once · Retreat in 2-3 weeks · Larval stages in tissues are not affected, necessitating retreatment
- Treatment of ascarids · 110 mg/kg PO · PO · once · Repeat in 21 days
- Treatment of ascarids · 100 mg/kg PO · PO · once · Repeat in 3 weeks
- Treatment of ascarids · 20-30 mg/kg PO once · PO · once
- Treatment of ascarids · 110 mg/kg (base) PO · PO · once · Repeat in 3-4 weeks · Retreating at 10-week intervals for P. equorum infections in young animals is recommended
- Treatment of ascarids · 200 mg/kg, PO · PO · once · Maximum of 80 grams in adults, 60 grams in yearlings, and 30 grams in foals
- Ascarids in poultry · 100-500 mg/kg PO once · PO · once · Repeat in 10-14 days · Not effective in psittacines
- Nematodes in raptors · 100 mg/kg · PO · once · Piperazine citrate
- Nematodes in parakeets and canaries · 0.5 mg/gram · PO · once · Piperazine citrate
- Ascaridia galli in poultry · 32 mg/kg (as base) (approximately 0.3 grams for each adult) · PO · once · Given in each of 2 successive feedings or for 2 days in drinking water · Citrate or adipate salts usually used in feed; hexahydrate in drinking water
- Ascaris suum and Oesophagostomum · 0.2-0.4% in the feed, or 0.1-0.2% in the drinking water · PO · once · Consume within 12 hours · Fasting or withholding water overnight may be beneficial. Retreat in 2 months. Safe in young animals and pregnancy.
- Ascaris suum and Oesophagostomum · 110 mg/kg (as base) · PO · once · Consume in 8-12 hours · Citrate salt usually used in feed as a one-day treatment, and hexahydrate in drinking water.
- Pinworms (Mice, rats, hamsters, gerbils, and rabbits) · Piperazine citrate in drinking water at 3 grams/liter · PO · continuous · 2 weeks
- Pinworms (Rabbits) · 100 mg/kg PO q24h · PO · q24h · 2 days · Piperazine citrate. Wash the perianal area.
- Pinworms (Rabbits) · Adults: 200-500 mg/kg PO q24h. Young rabbits: 750 mg/kg, PO once daily · PO · q24h · 2 days · Piperazine adipate. Wash the perianal area.
- Pinworms/tapeworms (Mice, Rats, Gerbils, Hamsters, Guinea pigs, Chinchillas) · 2-5 mg/mL drinking water · PO · continuous · 7 days, off 7 days and repeat · Piperazine citrate
- Treatment of ascarids · 45-65 mg of base/kg PO; for pups less than 2.5 kg: 150 mg maximum · PO · once · Retreat in 2-3 weeks · Larval stages in tissues are not affected, necessitating retreatment
- Treatment of ascarids · 110 mg/kg PO · PO · once · Repeat in 21 days
- Treatment of ascarids · 100 mg/kg PO · PO · once · Repeat in 3 weeks
- Treatment of ascarids · 20-30 mg/kg PO once · PO · once
- Nematodes · 40-60 mg/kg PO · PO · once · Repeat in two weeks · Follow with a fecal examination 14 days after the second dose. If positive, give a third dose and continue cycle until cleared.
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Chronic liver disease
- Chronic kidney disease
- Gastrointestinal hypomotility
- Chronic renal failure
- Hepatic impairment
- Heavy worm burdens (relative contraindication due to risk of intestinal impaction)
不良反應
- Diarrhea
- Emesis
- Ataxia
- Transient softening of feces (horses)
- Neurological signs at high doses (ataxia, tremors)
藥物相互作用
- Chlorpromazine · May precipitate seizures if used concomitantly (data conflicts, but caution is advised) · moderate
- Laxatives (Purgatives) · Not recommended; may eliminate piperazine from the GI tract before its full efficacy is established
- Pyrantel / Morantel · Antagonistic modes of action (pyrantel causes spastic paralysis, piperazine causes flaccid paralysis); should not be used together
- Pyrantel · Antagonistic mechanism of action (Pyrantel causes spastic paralysis, Piperazine causes flaccid paralysis) · major
- Morantel · Antagonistic mechanism of action · major
監測
- Clinical and/or laboratory efficacy (fecal examinations)
- Adverse effects (neurological signs, GI upset)
- Fecal flotation (to confirm clearance of roundworms)
- Adverse neurological signs
過量
Piperazine generally has a wide margin of safety (oral LD50 of piperazine adipate in mice is 11.4 g/kg). However, acute massive overdosage can lead to **paralysis and death**. **Feline Toxicity:** In cats, adverse effects occur within 24 hours after a toxic dose is ingested. Clinical signs include: * Emesis, hypersalivation, dehydration * Weakness, dyspnea, depression * Muscular fasciculations of ears, whiskers, tail, and eyes * Rear limb ataxia, head-pressing * Positional nystagmus and slowed pupillary responses *(Many of these effects may also be seen in dogs after toxic ingestions.)* **Treatment:** * Symptomatic and supportive care. * If ingestion was recent, use of **activated charcoal** and a cathartic is suggested. * Intravenous fluid therapy. * Keep the animal in a quiet, dark place. * Recovery generally takes place within 3-4 days.
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