User Rating 0.0 ★★★★★

Total Usage 0 times

Category Medicine & Tests

Clinical tool for healthcare professionals. Not a substitute for medical judgment. All conversions require clinical verification.

Source Medication

Current Dose (mg) Enter total daily dose in milligrams

Target Medication

Quick presets:

Select medications and enter a dose to see the conversion

Is this tool helpful?

Your feedback helps us improve.

★ ★ ★ ★ ★

About

Benzodiazepine cross-equivalency calculations carry real clinical risk. An error in conversion between agents with different receptor affinities and pharmacokinetic profiles can precipitate seizures, paradoxical excitation, or rebound withdrawal. This calculator uses the Ashton Manual diazepam-equivalency standard, where 10 mg oral diazepam serves as the reference unit. Each agent's factor (E) represents the dose in milligrams that produces an anxiolytic effect approximately equivalent to 10 mg diazepam. The model assumes linear dose-response proportionality, which is a simplification. It does not account for individual CYP3A4/CYP2C19 polymorphisms, hepatic impairment, or tolerance-induced receptor downregulation. All outputs require clinical verification.

Note: equivalency data varies between sources (Ashton, WHO, Stahl). This tool uses consensus midpoint values. Agents with active metabolites (e.g., diazepam → desmethyldiazepam) have effective durations far exceeding their parent half-life. The taper schedule generator approximates a 10% step-down protocol. It is a planning aid, not a prescription. Pro tip: always convert to diazepam equivalent first when switching agents, then calculate the target dose from that intermediate value.

Formulas

The conversion uses a linear proportional model anchored to the diazepam reference dose. Each benzodiazepine has a defined oral equivalency factor E, representing the milligram dose equipotent to 10 mg diazepam.

D_target = D_source × E_targetE_source

Where D_source = the current dose in mg, E_source = the equivalency factor of the current drug, E_target = the equivalency factor of the target drug, and D_target = the calculated equivalent dose in mg.

The intermediate diazepam equivalent is calculated as:

D_diazepam = D_source × 10E_source

For taper scheduling, the step-down dose at each interval n follows:

D_n = D₀ × (1 − r)ⁿ

Where r = the fractional reduction per step (default 0.10 for 10%) and n = the step number. The taper continues until the dose reaches a clinically negligible threshold.

Reference Data

Benzodiazepine	Diazepam Equiv. (mg)	Half-Life (hrs)	Onset	Active Metabolites	Primary Indication
Diazepam (Valium)	10	20 - 100	Fast	Yes	Anxiety, Seizures, Muscle Spasm
Alprazolam (Xanax)	0.5	6 - 12	Intermediate	No	Panic Disorder, GAD
Lorazepam (Ativan)	1	10 - 20	Intermediate	No	Anxiety, Status Epilepticus
Clonazepam (Klonopin)	0.5	18 - 50	Intermediate	No	Seizures, Panic Disorder
Chlordiazepoxide (Librium)	25	5 - 30	Intermediate	Yes	Alcohol Withdrawal, Anxiety
Oxazepam (Serax)	15	4 - 15	Slow	No	Anxiety, Alcohol Withdrawal
Temazepam (Restoril)	20	8 - 22	Intermediate	No	Insomnia
Triazolam (Halcion)	0.25	2 - 5	Fast	No	Insomnia (short-term)
Midazolam (Versed)	7.5	1.5 - 2.5	Fast	Yes	Procedural Sedation
Nitrazepam (Mogadon)	10	15 - 38	Intermediate	No	Insomnia, Seizures
Flunitrazepam (Rohypnol)	1	18 - 26	Fast	Yes	Insomnia (restricted)
Flurazepam (Dalmane)	15	40 - 250	Fast	Yes	Insomnia
Clobazam (Onfi)	20	36 - 42	Intermediate	Yes	Lennox-Gastaut Seizures
Clorazepate (Tranxene)	15	36 - 200	Fast	Yes	Anxiety, Seizures
Estazolam (ProSom)	1	10 - 24	Intermediate	No	Insomnia
Quazepam (Doral)	20	39 - 73	Intermediate	Yes	Insomnia
Prazepam (Centrax)	10	36 - 200	Slow	Yes	Anxiety
Halazepam (Paxipam)	20	14 - 100	Slow	Yes	Anxiety
Bromazepam (Lexotan)	6	10 - 20	Intermediate	No	Anxiety
Ketazolam (Anxon)	15	30 - 100	Slow	Yes	Anxiety
Medazepam (Nobrium)	10	36 - 200	Intermediate	Yes	Anxiety
Loprazolam (Dormonoct)	1	6 - 12	Intermediate	No	Insomnia
Lormetazepam (Noctamid)	1	10 - 12	Intermediate	No	Insomnia

Frequently Asked Questions

Benzodiazepine equivalency is not derived from a single definitive trial. Values are consensus estimates drawn from clinical observation, receptor-binding assays (Ki values at GABA-A subtypes), and pharmacokinetic modelling. The Ashton Manual, WHO guidelines, and Stahl's Prescriber's Guide use slightly different methodologies. For example, alprazolam equivalency ranges from 0.25 to 0.5 mg depending on the source. This calculator uses consensus midpoint values. Always cross-reference with your formulary.

Agents that undergo Phase I oxidative metabolism via CYP3A4 and CYP2C19 (diazepam, midazolam, alprazolam, triazolam) accumulate in hepatic impairment, effectively increasing their potency and duration. Agents that only undergo Phase II glucuronidation (lorazepam, oxazepam, temazepam - the "LOT" drugs) are preferred in liver disease because their clearance is relatively preserved. The calculator does not adjust for organ function. Manual dose reduction of 25 - 50% is typical for hepatically cleared agents in cirrhosis.

No. The taper schedule feature is a planning tool for clinicians. Benzodiazepine withdrawal can cause life-threatening seizures, particularly after prolonged use at high doses. The 10% reduction protocol is a common starting framework (Ashton Manual), but individual taper rates depend on duration of use, dose, half-life of the agent, and patient tolerance history. Medical supervision is mandatory.

Diazepam has the longest clinical history (approved 1963), extensive dose-response data, a wide range of available tablet strengths (2, 5, 10 mg), and a long half-life that permits smooth plasma-level transitions during cross-titration. Its active metabolite desmethyldiazepam extends the effective duration to 36 - 200 hours, which buffers against interdose withdrawal. These properties make it the preferred agent for taper conversions.

Not directly. Potency (the mass of drug needed for effect) is a pharmacological property unrelated to efficacy ceiling or abuse liability. Alprazolam at 0.5 mg is equipotent to 10 mg diazepam, but both produce equivalent receptor occupancy at those doses. However, high-potency, short-acting agents (alprazolam, triazolam) are associated with more severe interdose withdrawal and rebound anxiety, which can drive dose escalation. This is a pharmacokinetic risk, not a potency risk.

Benzodiazepines with active metabolites (e.g., diazepam producing desmethyldiazepam, nordiazepam) have effective durations much longer than the parent compound's half-life. This means the drug accumulates with repeated dosing over days to weeks. For conversion purposes, the steady-state effect is higher than a single-dose calculation suggests. The calculator provides the single-dose equivalency. In elderly patients, metabolite accumulation can cause oversedation, falls, and cognitive impairment days after the last dose.