プレガバリン
プレガバリンはガバペンチンに似たGABAの構造類似体であり、獣医療では主に**抗てんかん薬**および**神経障害性疼痛治療薬**として使用されます。 * **主な用途**: 難治性または複雑部分発作の補助療法、および慢性/神経障害性疼痛の管理。 * **臨床的特徴**: ガバペンチンの3〜10倍の効力を持つとされ、投与量を減らすことができるため、小型の動物に有利です。 * **安全性**: 一般的に忍容性は良好ですが、用量依存性の副作用として鎮静や運動失調が最もよく見られます。犬や猫における安全性と有効性に関する情報は現在限られていますが、増加しつつあります。
作用機序: Pregabalin is a structural analog of the inhibitory neurotransmitter **gamma-aminobutyric acid (GABA)**. Despite its structure, it does not bind directly to GABA receptors. * Binds with high affinity to the **alpha-2-delta (α2δ) subunit** of **voltage-gated calcium channels (CaV)** in the central nervous system. * Binding → Decreased calcium influx at nerve terminals → Inhibition of the release of excitatory neurotransmitters (e.g., **glutamate**, **substance P**, **norepinephrine**). * This reduction in excitatory neurotransmission produces its **analgesic**, **anticonvulsant**, and **anxiolytic** effects.
動物種別の用量
- Seizure disorders (anecdotal) · 1-2 mg/kg PO q12h · PO · q12h · Most commonly mentioned anecdotal dose.
- Seizure disorders (PK theory) · 1-2 mg/kg PO twice daily · PO · q12h · Theorized reasonable starting dose based on single-dose PK study.
- Neuropathic pain and seizures (extrapolated from PK study) · 4 mg/kg PO twice daily · PO · q12h · Would produce plasma levels within the extrapolated therapeutic range.
- Seizure disorders · 3-4 mg/kg PO every 8 hours · PO · q8h · To minimize side effects, initially start on 2 mg/kg and increase by 1 mg/kg each week until target dose is reached.
- Seizure disorders · gradually increased from 2 mg/kg PO to 3-4 mg/kg q8-12h · PO · q8-12h · Gradual increase needed to minimize sedation.
- Refractory seizures (adjunct therapy) · 2 mg/kg q8-12h, increasing 1 mg/kg/dose each week to a total of 3-4 mg/kg · PO · q8-12h · Used as a third anticonvulsant if control cannot be obtained with phenobarbital and bromides.
用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。
投与経路
禁忌
- Hypersensitivity to pregabalin
- Pregnant animals (toxicity demonstrated in experimental studies)
- Abrupt discontinuation
有害事象
- Sedation
- Ataxia
- Somnolence
- Dizziness
- Difficulty with concentration/attention/memory
- Blurred vision
- Dry mouth
- Peripheral edema
- Constipation
- Weight gain
- Syncope
- Congestive heart failure
- Renal failure (reversible)
- Rhabdomyolysis
- Hypersensitivity reactions (angioedema, rash, blisters, wheezing)
- Decreased platelet production
- Increased creatine kinase
薬物相互作用
- ACE Inhibitors (e.g., benazepril, enalapril) · In humans, coadministration may increase risks of edema and hives.
- CNS Depressants · May cause additive CNS depression.
- NSAIDs (e.g., ketorolac, naproxen) · In humans, cited as possibly reducing anticonvulsant effectiveness, though substantive evidence is weak.
モニタリング
- Efficacy (seizure frequency, pain scores)
- Adverse effects (sedation, ataxia)
- Seizure frequency and severity
- Pain scores
- Renal function (BUN, creatinine, USG)
- Hepatic enzyme activities (during prolonged therapy)
過量投与
There is limited experience with overdoses of pregabalin in veterinary medicine. One human ingested 8 grams without significant effect. There is no specific antidote for overdose. Standard decontamination protocols can be employed if indicated. Contact an animal poison center for more information.
VetSheet の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。