Drug Comparison
For educational purposes only — a decision-support tool, not a substitute for clinical judgment.
Side-by-side rubric across 96 psychiatric medications. Every rating traces to a verbatim primary-source quote — click any cell to see it.
How to read this tool ▾
Rating scale
– Favorable / lower than class baseline
± Minimal / equivocal
+ Low / uncommon
++ Moderate / common
+++ High / very common
++++ Very high / class-outlier
Frequency vs severity
F = frequency, S = severity. Each gets its own pill colored on the same traffic-light scale: green → blue → yellow → orange → red. Click any cell for incidence percentages and NNH.
Evidence tier
A Network meta-analysis / RCT / FDA label
B Cohort / registry / pooled label data
C Expert review / textbook / case series
Sourcing
Click any cell to see the verbatim source quote and citation. Missing data shows n/a.
Data depth
++ Graded — frequency + severity, primary-source traces
+ FDA label — §6 frequency only (dashed border). Click for sub-types.
Blank — not yet checked (not “absent”)
–±++++++++++ABCF = frequency · S = severity · Dashed border = FDA label only · Click cell for details
1 drug selected — Trihexyphenidyl(click to collapse)
1/4 selected
Trihexyphenidyl
Artane
Synthetic Anticholinergic Agent
FDA-approved indications
- All forms of parkinsonism (postencephalitic, arteriosclerotic, idiopathic) — as adjunct
- Extrapyramidal disorders from CNS drugs (antipsychotics, phenothiazines)
- Adjuvant therapy with levodopa for Parkinson disease
Off-label uses
- Generalized dystonia (younger patients tolerate well)
- Sialorrhea/drooling from clozapine
MechanismDirect parasympathomimetic inhibitor with relaxing effect on smooth muscle
Half-lifeUnknown for trihexyphenidyl (detailed PK information not available)
Decision GuideWhen to pick each / when to consider an alternative
Trihexyphenidyl
Consider when
- Chronic drug-induced parkinsonism — M1/M4-selective profile targets motor circuits with less peripheral burden than benztropine
- Generalized dystonia in younger patients — only anticholinergic with RCT evidence in pediatric/adolescent dystonia
- Need for rapid titration — short half-life (3–4 h) allows flexible dose adjustments within days
- Sustained-release formulation preferred — SR option available for smoother plasma levels and BID dosing
- +1 more
Consider an alternative when
- Acute dystonic reaction requiring parenteral treatment — no injectable formulation available (use benztropine IM/IV)
- Elderly patients — Beers list high-risk; cognitive impairment and falls risk increase sharply after age 60
- Tardive dyskinesia — anticholinergics may worsen TD; VMAT2 inhibitors are evidence-based alternatives
- History of substance use — highest abuse/euphoria potential among anticholinergics due to mild dopaminergic activity
- +1 more
| Axis | Trihexyphenidyl Anticholinergic |
|---|---|
| CNS | |
Dizziness | |
| Autonomic | |
Dry mouth (xerostomia) | |