In the US, almost 5 percent of the population above the age of 12 suffer from hypothyroidism. In most of the cases, the condition is typically mild I nature, though in a percentage of cases, the condition requires treatment. Among the different medications used for treating the condition, Levothyroxine, is considered popular, for treating an underactive thyroid gland. This in turn has a positive impact on energy levels and growth. Without exception all medications are associated with side effects, and Levothyroxine is no different. Here is a detailed look at the side effects of levothyroxine and suggested measures to mitigate/prevent side effects.
What is hypothyroidism and what are the common symptoms?
To understand the side effects of levothyroxine it is necessary to take a detailed look at the underlying condition and the symptoms. Hypothyroidism refers to the condition where the patient has an underactive thyroid, thereby not fully meeting the needs of the body. The gland is critical to manage the manner in which the body utilizes energy and therefore has an impact on every organ. When thyroid levels dip below the desired levels, the functioning of the body slows down, and this could impact the manner in which the heart beats. The most common symptoms from hypothyroidism includes gain in weight, pain in the muscles and joints, and abnormal fatigue despite lack of activity.
Other symptoms include drying and thinning hair, skin that is dry, and a puffy face. There is a possibility of individuals going into depression as a result of hypothyroidism. One of the biggest problems of the condition is its slow onset, which means that most patients remain unaware of the condition for a very long time. It is time to quickly look at the reasons behind hypothyroidism before diving into the side effects of levothyroxine. The condition is primarily attributed to one of many reasons; with the inflammation of the thyroid being the most common. Certain medications can cause the condition, while in some instances, the removal of part or full thyroid gland is the reason. Many individuals acquire the condition at birth through congenital hypothyroidism. Finally, the condition is also attributed to a possible lack of iodine in diet.
Overview and side effects of levothyroxine
It is time to dwell on the medication and learn all about the side effects of levothyroxine. The drug is the synthetic form of the endogenous hormone thyroxine, which helps replenish or make up for the inadequate production of T4 and T3 thyroid hormones. It works in a manner that is identical to the naturally secreted hormones. This then has genomic and non-genomic effects which in turn brings about an increase in the metabolic rates of the cells in the body, which in turn facilitate brain function, and other metabolic actions.
Ideal dosage to prevent side effects of levothyroxine
Some of the side effects of levothyroxine are mainly attributed to the incorrect dosage. The recommended dosage hinges on various factors, including age, the actual reason for the condition, the severity of the condition and other pre-existing conditions of the patient. It is available as oral tablets in strengths that typically begin at 25 mcg, ending at a maximum of 300 mcg. It is essential to understand here that the recommended dosages mentioned herein are the average ideal dosages, and will actually differ from individual to individual depending on various factors. The dosages mentioned herein are only for the purpose of reference.
To avoid side effects of levothyroxine as a result of wrong dosage, here are the typical average recommended dosages. Patients above the age of 18 and below 50 years of age, suffering from hypothyroidism are typically recommended a dosage that is not to exceed 200 mcg per day. Ideally, the calculation is 1.6 mcg per kilogram of body weight per day. Adults above the age of 50 years are generally given dosages between 12 to 25 mcg per day. For all other conditions, including goiter, thyroid cancer, individuals with heart ailments and pregnant women, the dose is determined by specific factors. Pregnant women are generally given a slightly stronger dosage due to the altered requirements.
Commonly reported side effects of levothyroxine
The various side effects of levothyroxine are typically classified as commonly reported side effects and serious side effects. This is a compilation of the possible side effects, and it does not necessarily mean that every patient on the medication would experience side effects of levothyroxine. Many are known to not experience any changes, while other experiences manifestations of the adverse effects. The commonly reported side effects of levothyroxine include an abnormal increase in appetite, sudden feelings of anxiety or nervousness. Individuals are known to turn irritable for trivial reasons, while many are known to experience abrupt changes in mood. The is the possibility of difficulty falling asleep, while many lose weight abruptly.
As a result of increased sensitivity to heat, patients are likely to sweat excessively, while the possibility of loss of hair also exists. This loss of hair is temporary in nature and patients are generally known to recover. Other possible side effects include vomiting and diarrhea that is not attributed to any other condition. Patients are also known to report changes in menstruation, while many experience cramps in the stomach. Headache and hyperactivity are some of the other conditions that are known to affect patients on the medication. Most of these effects are known to be mild in nature and will resolve quickly, without the need for medical intervention. However, in certain cases, it may be necessary for patients to seek medical assistance when the side effects are persistent or intense in nature.
Side effects of levothyroxine that are considered as serious in nature
The following side effects of levothyroxine are not commonly reported, but regarded as serious in nature. These effects may require urgent medical intervention, depending on the condition. For instance, patients on the medication with abnormal chest pain or difficulty in breathing may be experiencing the first symptoms of a heart attack. Similarly, symptoms such as swelling in the bottom limb extremities or rapid weight gain, with unusual tiredness are all indicative of a possible heart failure. Similarly, patients are also likely to experience a rapid increase in heart beat rate when on the medication. Finally, patients may also experience a change in heart beat rhythm, with the beats turning irregular.
Side effects of levothyroxine : drug interactions
There is the possibility of patients experiencing side effects of levothyroxine as a result of drug interactions. The contraindications could be with other prescription medications, supplements, herbal products or over the counter medication. It is essential to intimate the treating specialist about all conditions which will help prevent drug interactions. The actual nature of interactions includes an increase in the usual side effects, or it could result in a reduction in the potency of the medication or desired outcomes. Patients on medications such as antidepressants, blood thinners, ketamine and sympathomimetic drugs are likely to end up with possible aggravated side effects when combined with Levothyroxine. The typical interactions associated with any of these combinations include irregular heart beats known as arrhythmias.
Patients are exposed to the risk of increased heart ailments when levothyroxine is taken along with sympathomimetic medications. Other side effects of levothyroxine attributed to drug interactions include the heightened risk of bleeding when taken along with blood thinners. Specialists typically alter dosages to reduce the risk of bleeding. Patients on ketamine who take levothyroxine are at risk of ending up with increased blood pressure levels and rapid heart-beat rate. As mentioned above, another type of drug interaction is the possibility of a reduction in the potency of the medication. For instance, patients on medications that include certain types of antidepressants, certain anti-seizure drug formulations, antacids and calcium carbonate are more likely to experience diminished effects of Levothyroxine. It is therefore necessary to ensure that there is adequate gap between the various medications and levothyroxine or to alter dosages accordingly.
Finally, side effects of levothyroxine also include drug interactions that affect the potency of other medications. For instance, patients on certain medications to treat diabetes will experience a reduction in the levels of the medication in the body, when taken along with Levothyroxine. This necessitates a calculated increase in the dosage of the medication. Similarly, patients on certain medications belonging to the category of cardiac glycosides, are also generally recommended an increase in dosage. Finally, medications prescribed to treat wheezing or asthma related symptoms may also end up with lesser potency when taken along with levothyroxine.
Side effects of levothyroxine : regulatory warnings
The medication belongs to the category of drugs that have regulatory warning about its recommended use. A prescription only drug, it is not to be used off label to bring about weight loss or for treating obesity. Administering dosages higher than the recommended levels can have dangerous side effects. To avoid potential side effects of levothyroxine, patients are advised to strictly follow the recommendations and be aware of various warnings. Patients suffering from a sudden outbreak of allergies are advised to seek medical assistance at the earliest to prevent serious manifestations. Commonly reported symptoms of allergies include hives, wheezing, rashes, difficulty in breathing and swelling on the face, the tongue, throat and the lips. It is necessary to follow certain dietary modifications, as the medication is known to be affected by certain food products. For instance, soybean flour, walnuts, dietary fiber and cotton seed meal may have an impact on the manner in which the body takes in the drug. Therefore, patients on the medication are to make suitable changes to ensure that the medications mechanism of action is not affected.
Education: Master’s in Clinical Nutrition from Tufts University. Experience: 6 years of experience as a registered dietitian and freelance writer, creating content on nutritional science and weight management for various health websites.
