吡喹酮
吡喹酮是一種高效、廣效的**抗絛蟲**和**抗吸蟲**驅蟲藥，廣泛應用於獸醫學中。 主要臨床特點包括： * **廣效性：** 對犬貓的主要絛蟲種類（包括犬複孔絛蟲、帶絛蟲屬和包生絛蟲屬）具有高度療效。 * **抗吸蟲效力：** 也可用於標示外治療多種吸蟲感染（例如肺吸蟲、肝吸蟲）。 * **高安全性：** 通常非常安全，儘管注射劑型可能會引起短暫的局部疼痛或輕微的全身症狀。 * **合併療法：** 經常與其他抗寄生蟲藥物（如食子酸嘧啶、非班太爾、伊維菌素或莫昔克丁）合併使用，以提供全面的體內寄生蟲控制。 *臨床要點：* 由於吡喹酮會破壞寄生蟲的體壁，蟲體通常會被宿主消化。因此，在成功治療後，糞便中很少會觀察到完整的絛蟲。
作用機制: Praziquantel's exact mechanism is not fully elucidated, but it rapidly penetrates the parasite and alters the permeability of the cell membranes. * **Ion Flux Alteration:** Interacts with **phospholipids** in the parasite's integument → induces rapid intracellular influx of **calcium ions (Ca2+)**, as well as sodium and potassium fluxes. * **Spastic Paralysis:** The sudden calcium influx causes severe, sustained contraction and spastic paralysis of the worm's musculature, impairing sucker function and dislodging the parasite. * **Tegumental Destruction:** At higher concentrations, it causes irreversible focal vacuolization → subsequent disintegration of the cestodal integument. This exposes the parasite's internal antigens to the host's immune system and renders it susceptible to digestion by host enzymes. * **Trematodes:** Directly kills the parasite via similar calcium-mediated focal vacuolization and subsequent phagocytosis.
各物種劑量
- For susceptible cestodes (IM or SC) · <5 lbs: 11.4 mg (0.2 mL); 5-10 lbs: 22.7 mg (0.4 mL); >10 lbs: 34.1 mg (0.6 mL maximum) · IM/SC · Once · Using the 56.8 mg/mL injectable product
- For susceptible cestodes (Oral) · <4 lbs: 11.5 mg (½ tab); 5-11 lbs: 23 mg (1 tab); >11 lbs: 34.5 mg (1.5 tabs) · PO · Once · Using the 23 mg feline tab
- For susceptible parasites using combination product with pyrantel pamoate (Drontal) · Administer a minimum dose of 2.27 mg praziquantel and 9.2 mg pyrantel pamoate per pound of body weight according to the dosing tables on labeling. · PO · Once · May be given directly by mouth or in a small amount of food. Do not withhold food.
- For treatment of Paragonimiasis (Paragonimus kellicotti) · 23-25 mg/kg · PO · q8h · 3 days
- For treatment of Giardia infections · Give two small dog tablets of Drontal Plus (febantel 113.4 mg; pyrantel 22.7 mg; praziquantel 22.7 mg) · PO · Once daily · 5 days
- For Alaria spp. · 20 mg/kg · PO · Once
- For Spirometra mansonoides · 30-35 mg/kg · PO · Once
- For Taenia, Echinococcus, Dipylidium caninum, Mesocestoides (adult) · 5 mg/kg · PO/SC · Once
- For Diphyllobothrium (adult) · 35 mg/kg · PO · Once
- For Sparganum proliferum (adult) · 7.5 mg/kg or 25 mg/kg · PO/SC · Daily · 2 days
給藥途徑
禁忌症
- Puppies less than 4 weeks old (for solo product)
- Kittens less than 6 weeks old (for solo product)
- Known hypersensitivity to praziquantel
- Unweaned puppies or kittens (unlikely to be affected by tapeworms at this age)
- Animals weighing < 1 kg (specifically for spot-on preparations)
不良反應
- Oral (uncommon, <5%): Anorexia, vomiting, lethargy, diarrhea, salivation (cats)
- Injectable (dogs): Pain at injection site, vomiting, drowsiness, staggering gait
- Injectable (cats): Diarrhea, weakness, vomiting, salivation, sleepiness, transient anorexia, pain at injection site
- Anorexia
- Vomiting
- Lethargy
- Diarrhoea
- Transient hypersalivation (if spot-on application site is licked)
- Localized tissue sensitivity and pain at injection site (particularly in cats)
藥物相互作用
- Oxamniquine · Reportedly synergistic activity occurs in humans in the treatment of schistosomiasis; clinical implications in veterinary patients are unclear.
- Grapefruit juice · Can increase the area under the curve (AUC) of orally administered praziquantel by 150-200% in dogs.
- Dexamethasone · Concurrent administration may significantly decrease serum praziquantel concentrations. · moderate
- Cimetidine · May decrease the metabolic clearance of praziquantel, increasing its serum levels. · minor
監測
- Clinical efficacy (resolution of parasite infection)
- Fecal examination for tapeworm proglottids or eggs to confirm efficacy of treatment
- Monitoring for resolution of clinical signs (e.g., scooting, visible segments in feces)
過量
Praziquantel has a **wide margin of safety**. * **Rodents:** Oral LD50 is at least 2 g/kg in rats and mice. * **Dogs:** An oral LD50 could not be determined because doses >200 mg/kg induce vomiting. In ASPCA APCC reports, dogs exposed to overdoses showed no clinical signs. * **Cats:** Parenteral doses of 50-100 mg/kg caused transient ataxia and depression. Injected doses at 200 mg/kg were lethal. In ASPCA APCC reports, a minority of exposed cats showed clinical signs. *Treatment:* Overdoses are generally self-limiting (especially oral, due to vomiting). Provide supportive care if severe neurological or gastrointestinal signs occur.
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用,不能取代專業判斷或廠方最新藥品說明書。