Baclofen is a drug used to treat muscle spasms and is similar to the neurotransmitter GABA. It is currently being researched for its potential in treating addiction and withdrawal. But baclofen also has a potential for abuse and doesn’t come without side effects. Read on to learn about the uses, risks, and dosage of baclofen.
What is Baclofen?
Baclofen was first synthesized in the 1960s in the search for an anti-seizure drug. It was not effective for treating seizures, but researchers soon found that baclofen could be used to treat muscle spasticity, a condition that causes muscle spasms and stiffness .
Baclofen is used off-label for a number of other conditions, including helping manage alcohol dependence and acid reflux .
There are 3 ways baclofen can be administered :
- As a cream, where it is absorbed through the skin
- As oral tablets
- As injections directly into the spinal fluid (intrathecally), using an implanted pump
Is Baclofen a Narcotic?
Narcotics typically refer to opioid drugs, which baclofen is not. Baclofen does, however, fall under the broader category of ‘Central Nervous System Depressants’, drugs that can cause sedation and have a potential for abuse [2, 3].
Mechanism of Action
All GABA activity in the brain and nerves is “inhibitory”, meaning it blocks the release of other neurotransmitters brain cells use to communicate. By acting on GABA receptors, baclofen blocks the overactivation of nerves that may trigger muscle spasms, pain, brain damage, and mood changes [6, 7].
Much more is known about the effects of baclofen on pain and muscle spasms than on mood and addictive behavior .
What is Baclofen Used for?
1) Muscle Spasticity
Muscle spasticity occurs when the muscles continuously contract, causing spasms, tightness, and stiffness, which can interfere with everyday life. This condition is usually caused by damage to the nervous system .
Baclofen is a muscle relaxant that is FDA-approved to treat muscle spasticity that is associated with multiple sclerosis or spinal cord injury .
A systematic review of 25 clinical trials suggests that oral baclofen is effective for reducing muscle spasms and stiffness in cases of mild, moderate, and severe muscle spasticity regardless of the underlying cause .
Researchers also found that baclofen was at least as effective as other muscle relaxants, such as tizanidine and diazepam .
However, according to the same review, side effects were commonly reported with oral baclofen and affected between 25% to 70% of patients .
Baclofen is considered to be one of the first-line treatment options for muscle spasms associated with multiple sclerosis (MS) .
A 5-week randomized placebo-controlled trial of 106 patients with MS found that baclofen reduces spams, pain, and stiffness while improving movement .
Spinal Cord Injury
Baclofen is also approved to treat muscle spasticity due to spinal cord injuries .
A long-term randomized placebo-controlled trial of 93 patients with muscle spasticity due to spinal cord injury found that intrathecal injections of baclofen reduce rigidity, muscle spasms, and pain .
Baclofen is sometimes used for several off-label conditions, which we’ll discuss in the following sections. If you are prescribed baclofen, always take the medication as directed by your doctor.
Baclofen is sometimes used to help manage alcohol dependence, otherwise known as alcohol use disorder. There is some evidence that baclofen can help reduce cravings for alcohol and overall alcohol consumption .
For example, a study of 67 patients found that oral baclofen may reduce alcohol cravings .
In another 2-year observational study of 100 patients, 92% of participants reported suppressed alcohol cravings after taking oral baclofen .
A meta-analysis of 12 clinical trials found that baclofen is associated with higher rates of abstinence than placebo. However, the researchers also determined that baclofen did not decrease heavy drinking, craving, anxiety, or depression .
Another systematic review of 12 clinical trials including 1,128 participants concluded that there was not enough strong clinical research to determine if baclofen is more effective than placebo for alcohol use disorder .
3) Alcohol Withdrawal
Besides alcohol dependence, baclofen is also sometimes used to help treat alcohol withdrawal symptoms. Some small studies suggest that oral baclofen may reduce the physical symptoms of withdrawal, such as sweating, tremors, anxiety, and agitation [19, 20, 21].
For example, a randomized trial of 37 patients found that baclofen may be as effective as diazepam for treating alcohol withdrawal syndrome .
However, a systematic review of 3 clinical trials including 141 patients concluded that the clinical evidence that supports the use of baclofen for alcohol withdrawal is of very low quality. According to the researchers, there is not enough information to determine the effectiveness and safety of baclofen for this use .
4) Acid Reflux
There is evidence that baclofen may help reduce the symptoms of acid reflux, also known as gastroesophageal reflux disease (GERD). According to research, baclofen may help prevent the lower esophagus from relaxing, which is one of the causes of acid reflux .
A meta-analysis of 9 clinical trials including 283 patients with acid reflux may help reduce the number and average length of reflux episodes .
5) Cerebral Palsy
Baclofen is sometimes used in children and adolescents to help treat muscle spasticity associated with cerebral palsy .
According to a systematic review of 6 clinical studies, spinal (intrathecal) injections of baclofen can reduce short-term muscle spasticity in children with cerebral palsy. However, there was not enough evidence to determine its long-term effectiveness .
Oral baclofen does not appear to be effective for this condition. A review of 6 clinical trials with a total of 130 patients concluded there was not enough evidence to support the use of oral baclofen for muscle spasticity associated with cerebral palsy in children or adolescents .
A hiccup is caused by an involuntary muscle contraction of the diaphragm. While almost everyone experiences hiccups, a small number of people experience persistent hiccups that continue for days or months .
As a muscle relaxant, baclofen is sometimes used to help treat severe cases of persistent hiccups.
A systematic review of 15 studies including 341 patients found that baclofen may help treat persistent hiccups, although the quality of evidence is low .
Below are some reported side effects of baclofen. If any side effects persist or worsen, let your doctor know. This is also not a complete list of possible side effects. Tell your doctor if you experience any serious side effects or notice any effects not listed here.
Side effects can vary depending on the dose and how baclofen is administered (as an oral tablet, through an injection, or as a topical cream) .
Some common side effects include :
- Muscle weakness
- Dizziness (vertigo)
Some rare but serious side effects include :
- Swelling (edema)
- Difficulty breathing
Fatigue and sleepiness often occur at the start of oral baclofen treatment, especially if the dosage is increased too quickly, if the initial dose is large, or in older people. These side effects typically go away with time and can be reduced by decreasing the dosage.
Baclofen can cause withdrawal symptoms if suddenly discontinued after long-term use. If you want to stop taking baclofen, let your doctor know first.
- High fever
- Altered mental status
- Muscle rigidity
There are several case reports where abrupt discontinuation of intrathecal baclofen has led to death .
In the majority of cases, baclofen withdrawal symptoms are due to malfunctions or errors associated with intrathecal pumps. As mentioned earlier, baclofen can be administered through implanted automatic pumps. This is why it is important for patients and caregivers to monitor the pump to make sure it is always working correctly .
Baclofen should not be taken by those that are allergic or hypersensitive to baclofen or any of its components .
Pregnancy and Breastfeeding
The safety of baclofen in pregnancy has not been established. Pregnant women should discuss potential baclofen risks with their doctor to determine if baclofen is still needed.
There is evidence that baclofen use during pregnancy may cause preterm delivery, low birth weight, birth defects and withdrawal in newborn babies .
In one case report, the newborn baby of a woman taking 90 mg oral baclofen during pregnancy had seizures shortly after birth. In another case, a newborn baby experienced feeding difficulties. These may be symptoms of baclofen withdrawal and require special medical treatment with baclofen itself or other drugs [31, 32].
Baclofen has a potential for abuse. And although rare, some people become addicted to baclofen, especially with high doses.
In one case report, baclofen initially helped a 36-year-old man with depression and alcohol abstinence. However, he developed baclofen abuse due to its mood-enhancing effects and started to take higher and higher doses of the drug .
In one other case, a 29-year-old man on a smoking cessation program was prescribed 20 mg/day of baclofen. But he took 30 times the prescribed dose, which added up to 600 mg/day. He described a sense of wellbeing and pleasure from baclofen and a craving for it. As his baclofen dose was reduced, he experienced insomnia, irritability, anger outbursts, and tremors .
The following drugs have been reported to interact with baclofen. However, this is not a complete list, let your doctor know of all the medications and supplements you are currently taking to avoid any unexpected interactions.
Baclofen can interact with the following drugs :
- Other muscle relaxants
- Parkinson’s Disease drugs
- Anti-seizure drugs
- Antidepressants and lithium
- Drugs for high blood pressure
- Other drugs that affect kidney function, such as ibuprofen
- Opioid drugs for pain relief
- Drugs for insomnia or anxiety
- Antihistamines and sedatives
It’s not recommended to consume alcohol while on baclofen, since this can cause additional sleepiness, dizziness, and may even lead to coma.
The dosing of baclofen can vary. Always take this medication as directed by a doctor.
Oral baclofen is available as tablets with strengths of 5 mg, 10 mg, and 20 mg.
Patients are usually started at a low dosage, which is gradually increased until the desired effect is achieved. The lowest possible dosage needed to achieve the effect should be maintained.
Typical dosages range from 40 – 80 mg/day, while the maximum dosage should not exceed 80 mg/day.
When stopping baclofen, the dose should be gradually decreased over 1 – 2 weeks to avoid withdrawal symptoms.
Intrathecal Baclofen (Spinal Cord Injections)
Baclofen injections into the spinal cord (intrathecal) are indicated only in people with severe muscle spasticity from injury or multiple sclerosis who do not respond to oral baclofen .
The optimum dosage of intrathecal baclofen will individually vary depending on the disease type, symptoms, severity, side effects, and other factors. Patients are screened to determine if baclofen pumps should be implanted for continuous long-term baclofen infusions .
Initially, baclofen is administered in very small doses, which are gradually increased while side effects and clinical response are monitored by the healthcare team. Some people don’t respond to baclofen spinal injections. For those who do respond, daily doses are increased by 5 – 30% until a suitable maintenance dose is found .
The dose administration patterns can vary between individuals and include: simple continuous dosing, variable 24-hour flex dosing, or regularly scheduled administration .