In places with warm weather, Malaria is a big public health problem. A parasite causes this disease. Mosquitoes are the way of transmission to humans. Malaria can be deadly. When an infected mosquito bites a person, the symptoms can appear 10-15 days later. But this incubation period can vary.
The parasite attacks the blood cells. The symptoms that patients most commonly experience are similar to those of flu. But in more advanced cases, symptoms can include seizures and coma. These may cause death. Yellow skin, a medical condition known as Jaundice, is common for this infection.
This disease is almost nonexistent in most developed countries. But in Africa, the prevalence is still high. Malaria causes many deaths on this continent. The disease exists in some parts of South America and Asia also.
The parasites responsible for Malaria belong to the Plasmodium group. Five species of this microorganism can infect humans. The parasite enters the body through the saliva of infected mosquitoes. Female mosquitoes are the only ones that bite to suck blood. Hence, female mosquitoes are the main transmitters of this parasite.
Once in the body, the microorganisms reproduce in the liver. Of the five species of this parasite, P. falciparum is the most deadly. Other species (P. vivax, P. ovale, and P. malariae) are less aggressive. A fifth species, P. knowlesi, causes infections to humans in very rare cases.
Hence, health authorities implement different prevention methods in these risk areas where Malaria is endemic. Also, there is a need for effective treatments. This article describes one of the most efficient medicines against Malaria.
1. What is Lariam
Lariam (mefloquine hydrochloride) is a medication against Malaria. It is commercially available as tablets. These tablets contain 250mg of the active substance each. They are for oral administration. This medicine hampers the growth of the invading microorganisms in the bloodstream.
1.1 Treatment of Acute Malaria Infections
The most common treatment against Malaria uses a combination of two drugs. The first one is generally artemisinin. The second one can be lumefantrine or mefloquine (Lariam). It is possible to use quinine together with doxycycline to substitute artemisinin. Likewise, it is possible to use other chemical compounds as the second medication.
When the first symptoms appear, a visit to the doctor is mandatory. A blood test must confirm the presence of the disease. The treatment should begin only after positive confirmation. This will help avoid the problem of drug resistance. In some parts of Asia, for example, artemisinin is not effective due to resistance.
Lariam combats effectively acute Malaria infections by P. palcifarum and P. vivax. It is most effective against mild to moderate infections. It works well with susceptible and resistant parasite strains to mefloquine. Researchers have not documented its effect on the P. ovale and P. malariae species.
Doctors must be watchful with patients infected with P. vivax. While Lariam inhibits the growth of the parasites, it does not eliminate them from the liver. After the treatment with Lariam, a second treatment with primaquine is convenient. It is possible to use another similar chemical compound. This will eliminate the parasites from the liver and prevent a relapse.
1.2 Prevention of Malaria
Like with other diseases, prevention is better than therapy. Some of the most effective ways to prevent Malaria are:
- In the areas with Malaria prevalence, people must keep mosquitoes away. For example, people should use mosquito nets when sleeping;
- The use of mosquito repellents when doing daily activities;
- The use of insecticides to eliminate mosquitoes from houses and other premises;
- Removal of standing water to avoid the reproduction of mosquitoes;
- Introduction of some species of fish that eat mosquito larvae in ponds and lakes;
- Campaigns of vaccinations and immunizations.
The last point is useful for people that will travel to areas where malaria is common. Some drugs are available for this purpose. Lariam offers some protection against infections by P. palcifarum and P. vivax. It is effective against strains of P. palcifarum that develop resistance to chloroquine.
Children in some regions get a combination of sulfadoxine with pyrimethamine as prevention. Women with more than 3 months of pregnancy should get the same combination. There is only one Malaria vaccine available that lowers the risk of infection by 40%. But pharmaceuticals try to find more effective ones.
2. What you should know about Lariam
You should not consume Lariam unless prescribed by a doctor. There may be severe mefloquine side effects. Hence, only a health professional can recommend the use of this medicine.
2.1 Psychiatric or nerve problems
The use of Lariam may affect the nervous system. The patient may experience some mental problems and other unwanted effects. These are mefloquine long term side effects. These psychiatric problems can remain for a long time. Even if the patient stops taking the medicine, the problems may be still there. In some extreme cases, they can last for years or stay permanently.
Inform the doctor about your entire medical history. With this information, the doctor will assess the convenience of taking Lariam. The doctor will ensure the risk of suffering these long-term Lariam side effects is low. Discontinue the use of Lariam straight away if you experience some of these issues:
- Headache;
- Tinnitus;
- Dizziness or difficulty to keep balance;
- Lack of motion coordination;
- Abnormal states of mind, such as depression or suicidal thoughts.
Seek medical attention after experiencing any of the above effects.
2.2 Contraindications
You should refrain from using Lariam if you have suffered from mental illness before. These include anxiety, depression, and schizophrenia. Also, refrain from using this medicine if you have had seizures. For some life-threatening Malaria cases, the doctor still may prescribe Lariam. In this case, the benefit of saving your like will outweigh the danger of Lariam psychosis.
Inform the doctor about other medical conditions that you suffer or have suffered. For instance, disclose whether you have problems with the heart or liver. The doctor must know whether you have other conditions like epilepsy or diabetes. Inform if you have an allergy to some specific medicines. Allergy to mefloquine, quinine, or quinidine is of special interest in this case.
3. Medicine description
The main active substance of Larian is mefloquine hydrochloride. This drug dissolves slightly in water. It is a white crystal with a molecular weight of 414.78 g/mol. It is chemically analogous to quinine.
3.1 250-mg tablets
Besides the 250mg of the active substance, each tablet contains several inactive components. For the entire list of ingredients, you may read the package of the medicine. You should take these tablets after eating your main meal. Drink a tablet with abundant water (approximately 250 ml). If it is difficult to swallow it, you can crush it. Mix the resulting powder with a drink of your liking. This will ease the administration.
Taking Lariam may cause vomiting. This may happen within half an hour after the administration of this medicine. In such a case, you will need to take another dose. You should retake only half a dose if the vomiting happens between half-hour and one hour. If Lariam continues causing vomit, seek medical attention.
4. Mefloquine dose
You should never deviate from the doctor’s indications to take Lariam. Increasing or reducing the prescribed mefloquine dose can be counterproductive. Here you are some general recommendations to use this medicine for prevention:
- Unless otherwise indicated, you should take one dose a week. Choose a day for your dose each week (every Monday, for example);
- For better prevention, you should start taking this medicine at least 1 week in advance. This means taking the medication before you enter an area with Malaria prevalence;
- Use the medicine as described above in the area of risk. Do not discontinue the weekly doses when you leave the risk area. You should continue taking them for at least one month;
- If you discontinue the use of Lariam, make sure you use a different prevention method.
Besides this medicine, use other prevention methods mentioned earlier in this article.
4.1 Adult Patients
To combat the infection in adults, the recommended dose is five Lariam pills. You must take them all as a dose of 1250 mg. For your well-being, eat your main meal first. Use abundant water to swallow the dose. If this treatment does not yield a positive outcome within 2 or 3 days, the doctor should use a different drug. Likewise, if you used this medicine for prevention, a different medication should treat the infection.
For prevention, follow the recommendations listed above. If you use other medications, start taking Lariam 2-3 weeks in advance. This will help the doctor determine whether all the drugs have an interaction. There is a discussion about Lariam drug interactions later in this article.
4.2 Pediatric Patients
Doctors should not prescribe Larian to babies less than 6 months old. Only a doctor could prescribe it to treat Malaria in such a case. As a prevention measure, children under 20 kg of body weight should not use this medicine.
Having said that, the most convenient dose for infants is 20-25 mg per kg of body weight. This is a single dose. But, to avoid serious unwanted effects, the doctor may opt to divide the dose. The child could take 2 doses separated by a 6-8 hours interval. As already described, it is possible to crush the tablet if necessary. Then, you can mix it into water, milk, or any other drink.
As a Malaria prevention method, children must take a weekly dose too. This is 5 mg per kg of body weight. As a rule of thumb, you can use the doses summarized in the following table:
|
Weight of the infant |
Recommended weekly dose |
|---|---|
|
> 45 kg |
1 entire tablet |
|
30-45 kg |
¾ of a tablet |
|
20-30 kg |
½ of a tablet |
|
< 20 kg |
Do not use |
If there are no good results for treatment within 2-3 days, use a different drug. Likewise, if Lariam could not prevent Malaria, choose a different medication for treatment. Children are more susceptible to suffer from vomiting after taking this product. If this happens, follow the recommendations given earlier in this article.
4.3 Geriatric patients
There is no consensus about the use of Lariam in senior adults (+65 years old). Some researchers did not detect any difference with the treatment in younger patients. But some studies have reported cardiac abnormalities as a result of using this drug. Hence, the doctor has to assess the suitability of Lariam for a senior patient carefully.
5. What happens if you overdose
You may have some poisoning symptoms. In such a case, seek emergency medical attention. In the United States, for example, you can dial 911.
5.1 Symptoms and Treatment
Most commonly, you can have problems breathing after overdosing. You may as well pass out. Do not waste time and seek emergency medical attention.
5.2 Missing a dose
Missing a dose should not represent a big problem in therapeutic cases. You generally take a single dose of Lariam. So, you simply take the dose when you notice that you missed it.
6. What happens if you miss a dose
If you miss a dose of Lariam during a prevention treatment, take it at your earliest convenience. Then, take the next dose as scheduled. But if you miss the dose within a week before you enter a risk zone, contact the doctor. You will need a different prevention method.
7. What are possible Mefloquine side effects
With the recommended doses, Lariam is safe in most cases. But you may go immediately to a hospital in some emergency cases. For example, if you have an allergic reaction to the medication. Symptoms of such a reaction include swelling of your face and other parts. Problems with breath and hives are also indicators of an allergic reaction.
7.1 Clinical
Most side effects are mild and may include dizziness, vomiting, diarrhea, and symptoms like the flu. These symptoms do not require special medical attention. It will be difficult to distinguish these effects from the symptoms of Malaria.
7.2 Postmarketing
Most side effects in this category include vertigo, dizziness, and loss of balance. Other reported problems are:
- Sleep disorders (nightmares, insomnia);
- Cardiovascular disorders (high or low blood pressure, arrhythmias);
- Skin disorders (rash, pruritus);
- Muscular disorders (weakness, cramps);
- Respiratory disorders.
There are other effects reported. Not all are in the list above. People have reported visual problems, fatigue, malaise, and other ailments. One has to add the psychiatric and nerve problems mentioned earlier in this article.
7.3 Laboratory
In laboratory analysis, doctors have identified alteration of blood chemistry and composition. These alterations appear in all cases, whether patients use Lariam for treatment or prevention. These alterations remain even after several weeks of stopping the use of the medication.
8. Drug-drug interactions
Researchers have not studied in detail the drug-drug interactions. Hence, for your safety, inform the doctor about all other medicines that you are taking. This should include medicines that need no prescription. You should also inform about vitamin supplements and herbal products that you use.
The doctor will give special attention to:
- Medicines for cardiac diseases and hypertension/hypotension;
- Medicines against depression and other mental disorders;
- Medicines to control seizures;
- Medicines against tuberculosis;
- Vaccines with live agents.
Also, you should disclose any type of recreational drug that you use.
9. Long-Term Use
The long-term use of Lariam requires regular blood tests. Because of mefloquine toxicity, these tests are necessary to ensure that your liver is in good condition. Your vision may suffer too as a result of long-term use of Lariam. Consider visiting the ophthalmologist regularly.
10. Pregnancy Warnings
The following are some recommendations concerning the use of mefloquine during pregnancy.
10.1 Pregnancy Category C
Experiments with animals indicate that Lariam can affect the development of an embryo. But similar studies have not been conducted with pregnant women. There is no evidence that Lariam can affect human fetus. In any case, there must be a strong justification to use Lariam on a pregnant woman. Women traveling to a risk zone should avoid becoming pregnant. Ask your pharmacist for effective birth control methods.
10.2 Nursing Mothers
Mefloquine is present in small concentrations in breast milk. The drug can cause serious reactions to the baby. Hence, the doctor must determine whether to discontinue the use of Lariam. The doctor must assess the benefit to the mother versus the danger to the baby.
10.3 Pediatric Use
Multiple clinical trials support the use of Lariam in infants younger than 16 years old. In such cases, it is safe and effective with the recommended doses. Researchers have not documented properly the use in babies less than 6 months of age. It is better to avoid the use of Lariam for such young infants.
11. How to store medicine
Store your Lariam medication in a place without moisture. The temperature can vary between 15° C and 30° C. Ideally, it should be 25° C. Keep your tablets out of reach of children.