Why Do Muscles Twitch, Jerk and Spasm during Benzodiazepine Withdrawal?

What are the muscle twitches, jerks and spasms of benzodiazepine withdrawal?

A fasciculation is a small, brief twitch in a bundle of muscle fibers, seen as a ripple under the skin of an eyelid, a calf or a thumb. A jerk is a sudden movement of a limb or of the whole body, often at the moment of falling asleep. A spasm is a muscle that tightens by itself and stays tight, sometimes painfully.

All three are recognized symptoms of benzodiazepine withdrawal. Professor C. Heather Ashton listed muscle twitches, jerks and tics in the symptom table of the Ashton Manual, Chapter III, beside pain and stiffness in the limbs, back, neck and jaw, tremor, and the weak feeling she called “jelly-legs.” The 2020 boxed-warning update from the United States Food and Drug Administration (FDA) names abnormal involuntary movements, muscle pain and stiffness, and tremors among the symptoms a patient may have even when the dose is lowered gradually.

These movements are common, they are frightening, and in most patients they settle. So, why would lowering a medication taken for anxiety or sleep make a muscle jump?

Why does the nervous system fire the muscles without being asked?

Benzodiazepines strengthen the effect of gamma-aminobutyric acid (GABA), the chemical signal that quiets nerve cells. They are also efficient muscle relaxants. After months or years of steady use, the nervous system adapts to that extra quieting and comes to depend on it.

The medication works like a foot resting on a brake pedal. Over time the engine learns to push against the brake, and when the foot lifts too quickly the car lurches forward, even though nothing in it is broken. The instruction that follows is simple: ease off the brake slowly.

Professor Ashton described what happens when the brake comes off too fast. The nerves to the muscles become hyperexcitable, in her words, “leading to tremor, tics, jerks, spasm and twitching, and jumping at the smallest stimulus.” Muscle tension rebounds at the same time, which is where the stiffness and the aching come from.

This adaptation is called physical dependence, and it happens to patients who took their medication exactly as directed. Physical dependence is not addiction. In fact, the FDA’s 2020 update states that physical dependence can occur when benzodiazepines are taken steadily for several days to weeks, even as prescribed.

The same symptoms can also appear on a dose that has not changed. Professor Ashton observed that some patients on long-term benzodiazepines develop withdrawal symptoms while still taking the drug, because tolerance has developed, a pattern covered in the article on tolerance withdrawal.

Does twitching mean the nerves or muscles are being damaged?

This is the fear underneath most searches about fasciculations. A muscle that moves by itself, day after day, feels like the first sign of a serious neurological disease.

Professor Ashton’s answer was direct: “None of these symptoms is harmful, and they need not be a cause of worry once they are understood.” She compared the aching and stiffness to what any person feels after an unaccustomed bout of exercise. In her clinic, nerve conduction tests in patients with the tingling and burning sensations of withdrawal revealed nothing abnormal.

She also described three patients with numbness, muscle spasms and double vision who had been diagnosed with multiple sclerosis. The diagnosis, and all of the symptoms, disappeared soon after they stopped their benzodiazepines.

Withdrawal twitching is not a sign that a muscle or a nerve is being destroyed. It is a sign of a nervous system that fires too easily.

How long does it last? There is no fixed answer. Professor Ashton wrote that the oversensitive state left behind after the drug is stopped usually settles within a few weeks, though occasionally symptoms persist.

Her table of protracted symptoms (Chapter III, Table 3) describes cramps, tremor, jerks and spasms as gradually receding, although they may last at least a year and occasionally several years. In both cases the direction is the same, and the symptoms recede.

When should twitching or spasms prompt a call to the prescriber?

Withdrawal is the likely explanation for twitching that starts or flares after a dose reduction. However, it is not the only possible one, and a new symptom deserves a proper look before it is filed under withdrawal.

A patient should call the prescriber when twitching or spasms keep getting worse instead of coming and going, when they spread, or when a spasm is severe and will not let go. The same is true of real weakness that has built up over days or weeks, meaning a hand that drops things or a leg that cannot climb a stair, as opposed to the shaky “jelly-legs” feeling. Trouble swallowing or speaking that has come on gradually, or a muscle that is visibly shrinking, also needs an examination.

Withdrawal twitches and jerks happen to a person who stays awake and aware. A convulsion, a jerking episode with loss of awareness, or confusion afterward is a different event. For a seizure, a loss of consciousness, sudden weakness on one side of the body, sudden trouble speaking, or any other medical emergency, call 911.

Stopping suddenly makes the muscles worse, not better.

Unfortunately, a frightened patient sometimes decides that the medication is the problem and stops taking it. Professor Ashton wrote that rapid removal of the drug results in rebound overactivity of every system the drug had been damping down, and that rapid withdrawal can bring on convulsions, which are extremely rare with slow tapering. The FDA’s 2020 update is blunt about it: stopping abruptly or reducing the dosage too quickly can result in withdrawal reactions, including seizures, which can be life-threatening.

So, twitching during a taper is a reason to slow down. It is never a reason to stop overnight, and it is not a reason to hurry toward the finish either.

What helps while the nervous system settles?

The main tool is the pace of the taper. When twitching flares after a reduction, the usual response is to hold at the current dose until it calms, and then to make the next step smaller. Professor Ashton wrote in Chapter II that a person who reaches a difficult point can stop there for a few weeks if necessary, and that the person tapering, not the doctor, should be in control of the pace.

The Ashton Manual describes a crossover taper to diazepam (Valium) where it helps, because a slowly eliminated drug gives a smooth, gradual fall in blood level. It then describes reductions of up to one tenth of the dose at each step. The Maudsley Deprescribing Guidelines add hyperbolic reductions, in which each step gets smaller as the dose gets lower. Together they are the basis for a slow taper, which takes months and sometimes longer.

Comfort measures help the muscles themselves. Professor Ashton recommended stretching, moderate exercise, hot baths, massage and relaxation exercises, and she noted that they may give only temporary relief at first but help more when practiced regularly.

Gentle movement such as walking and slow stretching is the goal, and the article on exercise during a benzodiazepine taper covers how much is sensible. A physical therapist can teach a stretching routine for a neck, back or calf that keeps cramping.

Additionally, sleep, fluids and warmth matter, since fatigue and dehydration can make muscles more irritable, and heat loosens a tight one. Caffeine is a stimulant, and some patients find that cutting back quiets the twitching.

Supplements are a different matter. Magnesium, calcium, vitamin D and the B vitamins are often suggested for twitching. Yet, the evidence that any of them calms withdrawal symptoms is limited, and Professor Ashton wrote that there is no general need for dietary supplements or extra vitamins or minerals during withdrawal.

Response varies from person to person, so whether to try one is a question for a physician who understands the pharmacology. The article on magnesium during a benzodiazepine taper looks at one of them more closely. No supplement takes the place of a gradual taper.

What else do patients ask about muscle symptoms during a taper?

Why are the neck, shoulders and jaw so tight?

These are the muscles Professor Ashton named. She described stiffness of the limbs, back, neck and jaw, tension headaches that feel like a tight band around the head, and jaw and tooth pain from clenching during sleep. The same measures apply: warmth, gentle stretching, and a taper pace the nervous system can follow.

What if the benzodiazepine was first prescribed for muscle spasms?

Diazepam is sometimes prescribed as an add-on treatment for muscle spasm. Yet, a patient who has taken it that way for months or years has the same physical dependence as a patient who took it for anxiety, and needs the same gradual taper. The original problem needs its own plan as well, since stopping suddenly can bring the spasms back harder than before.

Is it safe to add a muscle relaxer for withdrawal spasms?

That is a decision for the prescriber, not a self-help step. Some muscle relaxers, carisoprodol (Soma) and baclofen among them, act on GABA systems of their own, and most of them sedate. A patient who already takes one alongside a benzodiazepine needs the two considered together in the taper plan, because a change to either one can change how withdrawal behaves.

A flare of twitching is first a question about pace.

Dr. Mark Leeds is an osteopathic physician and deprescribing specialist in Fort Lauderdale, Florida. When a patient reports that twitching or spasms have flared, his first response is a change of pace, a hold or smaller steps, and not a reflex toward another prescription. Most often, the muscles are reporting that the last reduction came too soon or was too large.

The patient directs that pace. There is no deadline, a hold is not a failure, and a small step back up after a cut that proved too large is a legitimate choice. Fortunately, with time and a taper the nervous system can follow, the twitching quiets in most patients.

Dr. Leeds’ practice offers medically supervised tapering of benzodiazepines and z-drugs to patients in Florida. Contact Dr. Leeds to ask about a taper that moves at the patient’s pace.

This article is educational. It is not medical advice, and reading it does not create a doctor-patient relationship. Decisions about starting, continuing, or tapering any medication should be made with your own physician.