Spasm plans start at 2 mg. The CYP1A2 wall is not optional.

Margin notes on the 2 mg start

Residents write 4 mg TID on day one because '2 mg does nothing'. Peak is 1-2 hours. Ask when they swallowed relative to the exam.

Oral contraceptives are a 1A2 caution, not the fluvoxamine ban. Still write them on the list.

Other alpha-2 agonists plus tizanidine is a hypotension stack. Do not 'add a bit of clonidine for sleep'.

The cash lock is the 2 mg tablet thirty-count. Capsule cash is another row. Name the form on the e-script.

Hypotension, liver enzymes, and a slow stop

Monitor for hypotension, especially with other antihypertensives. Do not pair tizanidine with other alpha-2 agonists. First-dose 2 mg can still drop pressure in a dry, fasting patient.

Liver injury is a labelled risk. Check ALTs as the label asks. Stop if liver injury appears.

Hallucinations are a stop-and-review event. So is severe sedation that makes driving impossible.

Coming off: taper. Abrupt stop after regular use can rebound hypertension, tachycardia, and hypertonia. That is section 2.2, not optional courtesy.

Thirty-three times the exposure is a contraindication

Fluvoxamine plus a single 4 mg tizanidine raised Cmax 12-fold, AUC 33-fold, and half-life 3-fold in ten healthy subjects. Ciprofloxacin raised Cmax 7-fold and AUC 10-fold. Hypotension and psychomotor impairment were the clinical picture.

Those pairs are contraindicated. There is no 'use 2 mg instead' escape. Psychiatry cover matters: fluvoxamine for OCD sits on the same enzyme.

Other CYP1A2 inhibitors - zileuton, other fluoroquinolones, amiodarone, mexiletine, propafenone, cimetidine, famotidine, oral contraceptives, acyclovir, ticlopidine - are avoid-or-caution, not the same absolute sentence as fluvoxamine and cipro.

Smoking can induce 1A2 and lower levels. Quitting can raise them without any tablet change.

How 2 mg becomes a day's work

Start 2 mg. Repeat q6-8 h, maximum three doses in 24 hours, while you learn the sedation. Then raise by 2-4 mg per dose every 1-4 days if spasm still wins.

Unequal doses appear in the trials (more at night, less in the morning). That is a prescriber pattern, not a patient invention on day two.

Ashworth scores in the maintenance phase were read within 2.5 hours of a dose. If someone says 'it never works', ask when they swallowed relative to the transfer.

Why the exam has to sit inside the 2.5-hour window

Pivotal tone scores were read within about 2.5 hours of a dose. A Friday clinic at 16:00 after a 08:00 2 mg is a visit that will call the drug a failure.

Write the swallow time on the appointment note. If the person cannot time a dose to clinic, say so and judge spasm at home with a transfer log instead.

Unequal doses in the trials - more at night, less in the morning - existed because night spasm and morning sedation fight each other. Copying a flat 8 mg TID from a textbook skips that fight.

Three doses in 24 hours is the start cage. It is also a reminder that this is not a once-daily baclofen substitute. The half-life is 2.5 hours.

A first 2 mg on an empty-stomach capsule can drop pressure in a dry MS patient. Sit for a minute after the first-ever swallow if the ward allows.

Ciprofloxacin for a rehab UTI is still contraindicated at 2 mg. The interaction study used 4 mg, but the label does not give you a 2 mg exception.

Coming off after weeks at 16-24 mg without a taper is how Sunday rigidity and a 170 systolic get blamed on a new plaque. Slow the exit unless an emergency hold (fluvoxamine, cipro, jaundice, hallucination) forces an abrupt stop.

The cash lock is 2 mg tablets x 30. If the box is capsules, the food curve changed. Retitrate. Name the form every time.

Three swallows, not a grazing bottle

The start rule is three doses in 24 hours. People with a bottle on the nightstand graze every time a spasm twitches. That is how 36 mg appears before anyone meant to titrate.

Write the three clock times on a card if PRN use is the plan. If a fourth spasm cluster arrives, it is a next-day call, not a fourth 2 mg.

Night-heavy unequal dosing is a trial pattern. It still counts toward the daily total and the three-dose cage at the start.

Food plus form plus a fourth swallow is how hypotension and a nap in a tram seat get written as 'MS fatigue'.

If spasm is worse only at night, move milligrams toward evening with the prescriber rather than adding a dawn fourth tablet. The three-dose cage still counts night swallows.

A new fluvoxamine script from psychiatry is the same hard stop as ciprofloxacin. Hold tizanidine. Do not 'watch one dose'. The 33-fold study used a single 4 mg.

Oral contraceptives, cimetidine, and some antiarrhythmics are caution lanes, not that absolute pair. Still write them down before the next 2 mg rise.

Smoking cessation without a dose review is how a previously 'fine' 8 mg becomes a fall. Plan the visit around the quit date.

Name capsule or tablet on every refill. A winter generic swap is a new curve, not the same 2 mg feeling.

When to draw the liver tests

Liver injury is a labelled risk. Aminotransferases belong on the plan when tizanidine will be more than a rare PRN. The exact calendar is the prescriber's, but 'never check' is not a plan.

New anorexia, dark urine, or right-upper-quadrant pain is a hold. Do not raise from 2 mg to 8 mg in the same week a new statin and a new antibiotic also landed.

Hepatic impairment increases exposure. A first 2 mg in that setting can behave like a larger swallow. Specialist ownership is the difference between a cautious start and a contraindicated gamble.

Inactive metabolites linger 20-40 hours. A 'normal ALT last year' does not cover a new 36 mg day.