Is Levothyroxine a Drug of Abuse?

What is Levothyroxine? It is a generic drug typically found as the brand name Synthroid. It is a synthetic hormone prescribed to treat hypothyroidism, which occurs when the thyroid does not produce enough hormone to maintain a normal body weight, height, and physical energy. The medication can also be found as the brand names Levothroid, Levo-T, Levoxyl, Tirosint, and Unithroid. The Food and Drug Administration (FDA) approved this medication officially in 2000, but the prescription has been used in the United States since the 1950s.

This synthetic thyroid hormone treats not just congenital hypothyroidism, but age-related hypothyroidism, which is most common in women over 60 years old. Levothyroxine can also help manage symptoms associated with thyroid cancer or an enlarged thyroid gland (goiter). Levothyroxine replaces thyroid hormone in the body when the thyroid cannot produce enough or when the thyroid has been removed via surgery

What Is Hypothyroidism?

Signs of hypothyroidism or another thyroid problem include:

  • Poor physical growth
  • Slow speech
  • Lack of energy
  • Excessive fatigue or tiredness
  • Weight gain
  • Constipation
  • Hair loss
  • Dry, thick skin
  • Joint and muscle pain
  • Increased temperature sensitivity, especially to cold
  • Depression

People who have normal thyroid function do not need synthetic hormones to manage thyroid issues, but in some cases, people have abused this drug as a performance-enhancer, a way to lose weight, or as a way to boost physical energy. Abusing this substance for nonmedical or self-medicating reasons can lead to severe, life-threatening side effects.

Issues Affecting California


Side Effects Associated with Levothyroxine

People who take levothyroxine are at a certain risk of experiencing side effects even if they take this medication as prescribed. However, side effects that are unmonitored or untreated are more likely to become serious. People who abuse levothyroxine are at a greater risk for developing uncomfortable side effects, which may become serious over time.

Common side effects associated with levothyroxine include:

  • Weight loss
  • Physical tremors
  • Nausea, vomiting, and stomach cramps
  • Diarrhea
  • Headache
  • Nervousness
  • Irritability
  • Excessive sweating
  • Increased appetite
  • Fever
  • Sensitivity to heat
  • Temporary hair loss
  • Insomnia

Severe side effects that can be life-threatening include:

  • Chest pain
  • Irregular pulse
  • Rapid heartbeat

Long-Term Physical Effects

Because women struggle with acquired hypothyroidism more often than men, women are prone to experiencing more serious side effects from taking this medication. When a woman is over 60 years old, she is more likely to develop osteoporosis in general, but taking levothyroxine appears to make the condition more likely to occur. This medication can decrease bone mineral density over time, and women are more susceptible to this effect than men. A study published in the Journal of Preventive Medicine & Public Health in 2014 found a correlation between older women taking levothyroxine and broken bones.

Cardiovascular damage may also be a side effect of levothyroxine. Signs of a heart attack like shortness of breath and chest pain, signs of heart failure like extreme tiredness and swelling in the legs, irregular heart rhythm, or a very fast heartbeat should all be taken seriously—get emergency medical treatment. While these symptoms may appear suddenly, the damage done to the heart may take time.

One unusual side effect called choreoathetosis is associated with abuse of levothyroxine or taking too much of this drug. This is a movement disorder in which the body involuntarily twitches or writhes, leading to impaired functioning in daily life. This condition prevents normal movement and walking, and in severe cases, it can lead to disability. A report published in 2009 found that thyrotoxicosis from abusing levothyroxine could trigger choreoathetosis; once the patient stopped taking levothyroxine, though, her symptoms cleared within one week.

Abuse of Levothyroxine to Lose Weight or Enhance Performance

Abusing levothyroxine to lose weight or increase physical energy is not a common practice, but it does occur, especially among athletes. This group is more likely to abuse drugs like this to fool drug tests while getting benefits similar to those of stimulants. A Daily Mail report from 2015 highlighted the story of a bronze medal-winning runner who had been pressured by her trainer to take levothyroxine to lose weight in order to compete again.

Although levothyroxine may be misused or abused by some athletes to lose weight for competitions, the World Anti-Doping Agency (WADA) has not yet listed this medication on their list of forbidden substances. Despite its dangers, athletes are currently free to take this drug even if they have normal thyroid function.

Athletes may abuse levothyroxine as a performance-enhancer, but sometimes, others abuse it to lose weight. Stimulants like Adderall and cocaine have been abused for this reason, and they are more commonly found as drugs of abuse among people who have eating disorders. However, levothyroxine has sometimes been found as a drug of abuse in these cases.

Withdrawal and Overdose from Levothyroxine

Withdrawing from levothyroxine is not dangerous. In fact, if the drug is abused, quitting is safer than continuing, but it may include a resurgence of symptoms associated with the underlying thyroid problem. Symptoms include rapid weight gain, depression, low energy, and dry skin. People who abuse levothyroxine may develop insulin resistance during withdrawal, which can trigger diabetes.

When taken as prescribed, levothyroxine is a safe medication to treat thyroid-related disorders. However, when this drug is abused, or mixed with substances that increase the drug’s potency, there is a risk of overdose. Call 911 immediately if someone displays the following signs of a levothyroxine overdose:

  • Intense headache
  • Leg cramps
  • Physical tremors that are not controllable
  • Extreme nervousness
  • Irritability
  • Chest pain
  • Rapid, pounding heartbeat
  • Shortness of breath
  • Very high fever, leading to hyperthermia

Other signs that too much levothyroxine has been taken include warm or feverish skin due to blood flow changes and increased metabolism; gastrointestinal discomfort; anxiety or restlessness; trouble concentrating; and memory loss.

Dangers of Mixing Levothyroxine With Other Prescription or Illicit Medications

Since levothyroxine is a hormonal supplement, this medication will interact with many different prescriptions. It is important to be clear with the prescribing physician about any substances that are taken, including illicit drug abuse, potential alcohol abuse, and other prescription medications. It is also important to notify the doctor of any history of drug or alcohol abuse.

Substances that may interfere or interact negatively with levothyroxine include:

  • Amphetamines, including Adderall or illicit amphetamine drugs
  • Aspirin
  • Blood thinners line warfarin
  • Antidepressants or anti-anxiety medications
  • Heart disease medications
  • Antiseizure drugs
  • Oral contraceptives
  • Insulin and other diabetes medications
  • Ketamine

Professional Help to End Levothyroxine Abuse and Prevent Relapse

Abusing drugs or alcohol requires evidence-based treatment that starts with detox, follows through a rehabilitation program, and continues with ongoing support from loved ones, peer support groups, and potentially an individual therapist, counselor, life coach, or spiritual or religious leader. Once rehabilitation is complete, it is important to keep focused on recovery and sobriety with help from a community that has been through similar struggles. Support groups are great for this form of emotional help.

A good starting place for all kinds of support, including mutual support groups or different approaches to rehabilitation, can be found through the Substance Abuse and Mental Health Services Administration’s online treatment finder.

Support groups for prescription drug abuse include SMART Recovery and Pills Anonymous (PA). Additionally, if a prescription drug like levothyroxine was abused as part of an eating disorder problem, treatment for this co-occurring disorder is important. Help can be found through the National Eating Disorders Association (NEDA), both through their helpline and through their online support group finder.

Evidence-based detox and rehabilitation are the most effective ways to overcome substance abuse, including abuse of prescription drugs like levothyroxine. However, between 40% and 60% of people who struggle with addiction will experience relapse. The National Institute on Drug Abuse (NIDA) states that relapse is part of the chronic disease of addiction. A focus on aftercare when rehabilitation has been completed can help to reduce the risk of relapse and get one back into treatment faster when relapse does occur. This is crucial as addiction can still be effectively managed after relapse.

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