Potassium Chloride
Severe
Database
Clinical effect not specified
Source: DDInter
Drug reference
procyclidine
Antimuscarinic (antiparkinsonian / anti-EPS) · Antiparkinsonian
START
2.5 mg PO three times daily (acute dystonia: 5–10 mg IM/IV)
TYPICAL MAX
~30 mg/day (oral)
STOP IF
Anticholinergic delirium, ileus, or acute glaucoma
WATCH
Cognition (elderly), bowel/bladder, IOP risk, temperature
CDSCO approvedATC N04AA04
KDIGO 2024 + manufacturer label
- ONSET
- 36min · absorption
- PEAK
- 1.5h · peak effect
- t½
- 12h · t½
- DURATION
- 5h · per dose
EXCRETION
Renal/biliary — metabolites
route + CYP
INTERACTIONS
4 major
SEVERE in our sources
PREGNANCY
Use only if clearly needed; limited data.
FDA category + note
Top interactionssee all 8 →
- Potassium ChlorideSevereDatabaseDDInter
- Potassium CitrateSevereDatabaseDDInter
- TopiramateSevereDatabaseDDInter
- ZonisamideSevereDatabaseDDInter
Mechanism
Central muscarinic acetylcholine receptor antagonist that restores the dopamine–acetylcholine balance in the striatum, relieving drug-induced extrapyramidal symptoms and parkinsonian tremor/rigidity.
Indications
Drug-induced extrapyramidal symptoms (acute dystonia, parkinsonism)Parkinson disease (tremor-predominant, adjunct)Acute dystonic reactions (parenteral)
Dosing
- Adult
- Parkinsonism/EPS: 2.5 mg PO three times daily, titrate to 10–30 mg/day. Acute dystonia: 5–10 mg IM/IV (repeat if needed).
- Pediatric
- Acute dystonia (specialist): weight-based parenteral.
- Renal adjustment
- No specific adjustment.
- Hepatic adjustment
- No specific adjustment; caution in significant disease.
- Geriatric
- Lower doses; high anticholinergic/confusion risk.
- Max dose
- ~30 mg/day (oral)
Pharmacokinetics
Onset
Oral ~30–45 min; IV acute dystonia within minutes
Peak effect
~1–2 h (oral)
Duration
~4–6 h (oral)
Half-life
~12 h
Bioavailability
Well absorbed orally
Protein binding
Moderate
Metabolism
Hepatic
Excretion
Renal/biliary (metabolites)
Contraindications
- Angle-closure glaucoma
- GI/GU obstruction; severe ulcerative colitis/megacolon
- Myasthenia gravis
- Hypersensitivity
Side effects
Common
Dry mouthBlurred visionConstipationUrinary retentionDizzinessConfusion (elderly)
Serious
- Anticholinergic delirium/psychosis
- Acute angle-closure glaucoma
- Hyperthermia (anticholinergic, hot environments)
- Paralytic ileus
- Tachyarrhythmia
Pregnancy & lactation
Pregnancy
Use only if clearly needed; limited data.
Lactation
May suppress lactation; limited data — caution.
Drug interactions
Potassium Citrate
Severe
Database
Clinical effect not specified
Source: DDInter
Topiramate
Severe
Database
Clinical effect not specified
Source: DDInter
Zonisamide
Severe
Database
Clinical effect not specified
Source: DDInter
Metoclopramide
Moderate
Database
Antagonised prokinetic effect
Anticipate; monitor GI function
Source: Kimi deep-research + Cla
Antipsychotics
Moderate
Database
Used to counter EPS but masks tardive dyskinesia
Use lowest effective dose; reassess need
Source: Kimi deep-research + Cla
Cholinesterase Inhibitors
Moderate
Database
Pharmacologic antagonism
Avoid combination
Source: Kimi deep-research + Cla
Other Anticholinergics
Moderate
Database
Additive antimuscarinic load
Avoid stacking; monitor (esp. elderly)
Source: Kimi deep-research + Cla
4 additional low-confidence interactions hidden — those rows lack a documented mechanism or management plan in our sources.
Related guidelines
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Sources: KD Tripathi 7e·Verified: 2026-05-20 · House clinical team·Cockpit curated: 2026-05-20