Duloxetine (Oral)

Overview

Duloxetine is often prescribed as a means to treat either anxiety or depression. It is also used to relieve the pain caused to patients suffering from nerve damage due to diabetes (also known as diabetic peripheral neuropathy).

It can also be used to treat muscle pain and stiffness (fibromyalgia), as well as the long-lasting, chronic pain related to bones and muscles.

The drug Duloxetine is a part of a group of drugs known as SNRIs, which stands for selective serotonin and norepinephrine reuptake inhibitors. Essentially, these work by increasing the activity of norepinephrine and serotonin in the brain.

To obtain Duloxetine, a patient must first undergo a full medical examination and then receive a prescription. This drug has the potential to cause a wide variety of adverse side effects and is strictly suitable for certain patients only. For this reason, never seek to obtain and use Duloxetine on your own.

Condition(s) treated

  • Depression

Type of medicine

  • Capsule

Side Effects

Just like most other drugs, Duloxetine can potentially cause a wide range of different side effects to occur. Some of these are not very serious, but others are more so. If you experience any of the side effects as listed directly below, then contact your doctor immediately for assistance.

Incidence not known

  • Increased thirst

Below are symptoms of you possibly having overdosed. If you experience any of these, then you should contact emergency medical assistance.

  • Twitching

As well as these, there are other side effects that you can experience which are not necessarily as serious. You may find that these effects will pass or diminish as your treatment continues and your body becomes adjusted to the medicine. However, if you are experiencing any of the side effects listed below, and if they are worrying you at all, then you can still contact your doctor. They may be able to advise on means to reduce the effects, such as by altering your dosage.

More common

  • Sleepiness or unusual drowsiness

Less common

Loose stools

  • Abnormal orgasm

Though this list of possible side effects is extensive, it is not necessarily all-inclusive. If you experience other side effects as a result of taking Duloxetine, you may still want to seek advice from your doctor if you are at all worried.

Dosage

The exact dosage you receive through from your doctor will depend largely on your exact medical condition and the nature of your problem. It will also factor in any other medication you take, as well as the strength of your Duloxetine capsules and how frequently you are supposed to take them. Below you can find the average dosages that are given. However, you should not alter your own prescription in any way, unless otherwise instructed to do so by your doctor.

For delayed-release capsules when treating anxiety:

  • Adults. At first, take 60mg one time per day. In some cases, you may need to take 30mg once per day for 1 week leading up to the 60mg per day. As your treatment progresses, your doctor may alter your dosage as needed. But it usually won't be more than 120mg per day.

For delayed-release capsules when treating chronic muscle pain:

  • Adults. Take 60mg once per day. You may need to start taking 30mg once per day for a week leading up to this.

For delayed-release capsules when treating depression:

  • Adults. Take 40mg each day, made up of two 20mg doses. Alternatively, take 60mg per day, given either in one dose or as two 30mg doses. As your treatment progresses, your doctor may alter your dosage as needed. But it usually won't be more than 120mg per day.

For delayed-release capsules when treating diabetic peripheral neuropathy:

  • Adults. Take 60mg once per day.

For delayed-release capsules when treating fibromyalgia:

  • Adults. Take 60mg once a day. In some cases, you may need to take 30 mg once per day for a week leading up to this.

If you miss a dose for any reason, then you should take it as soon as you realize. However, if it is almost time for you to take your next dose, you should just go ahead and skip the missed dose. It is important that you never double dose.

You should be careful in following the exact prescription as laid out by your doctor. This will maximise any benefits you receive from the drug, and limit any unwanted side effects. Do not take more of it than as prescribed and do not continue to take it after your treatment has ended.

When picking up your medication, you will find a Medication Guide accompanying it. Familiarise yourself with this and address any questions to your doctor.

When taking the delayed-release capsules, do not break, crush or chew the capsules. Instead, take it whole either with or without food. You should never break the capsule and sprinkle the contents into a drink or over food.

As a part of your treatment, you will need to take this medicine for several weeks. You may find it is a long time before you start to see any results. Regardless of this, keep taking the medicine as prescribed, and address any concerns or queries to your doctor.

Interactions

Duloxetine is known to interact with a variety of different things, including a wide range of other drugs. Directly below is a list of drugs with which it is not recommended you take Duloxetine. Your doctor will first consult with you before prescribing this medication so be careful in informing them of all drugs you currently take. In particular, make them aware if you currently use any of the following. Taking Duloxetine with the following can lead to unpleasant or harmful interactions. For this reason, your doctor may likely choose to prescribe you a different drug instead.

  • Selegiline
  • Isocarboxazid
  • Thioridazine
  • Phenelzine
  • Safinamide
  • Bromopride
  • Tranylcypromine
  • Linezolid
  • Procarbazine
  • Metoclopramide
  • Rasagiline
  • Methylene Blue

As well as this, there are other drugs that are known to interact, but it may still be necessary to take the two together. Again you should inform your doctor if you take any of the following. They may choose a different drug instead, or alternatively, they may alter your dosages of one or both so as to limit any interactions.

  • Nepafenac

Below is another list of drugs, which this time are known to cause an increased chance of certain side effects if taken alongside Duloxetine. Agin, it may still be necessary for you to take both drugs, in which case your doctor may alter your dosages or frequency of one or the other.

  • Warfarin

There is also the possibility that Duloxetine could interact with other parts of your dietary intake. This includes what you eat, drink, and how much you smoke. In particular, using alcohol and tobacco whilst taking this drug could cause interactions to occur. With regards to tobacco, your doctor may request that you limit your intake. If not possible, they may need to reduce your dosage of Duloxetine. You should be clear and honest with them about your typical daily diet.

Finally, other medical problems you currently have could possibly interact with this drug. Your doctor will discuss your medical history, but in particular, will need to know about any of the following medical problems.

  • Kidney disease. You should use Duloxetine with caution as your body will more slowly remove the medicine from your system, thus increasing the effects it has

Warnings

Before being prescribed Duloxetine, it is important your doctor knows the full extent of your medical circumstances. This way they can anticipate any possible interactions or side effects, and make adjustments accordingly. As a part of our initial consultation, make clear any allergies you suffer from. This includes those to animals, preservatives, dyes, other drugs, and of course Duloxetine.

When treating anxiety, the appropriate studies that have so far been conducted have not highlighted any problems that would limit their effectiveness in children. However, it is important to note that these studies have only been established for children aged 7 and above. For those younger than 7, your doctor will need to decide whether this is a safe and suitable drug to take.

For other indications in the pediatric population, no studies have been performed on the relationship between the effects of the drug and age. Again, the prescribing doctor is best placed to weigh up all benefits and potential risks.

With regards to elderly patients, appropriate studies performed have not highlighted any geriatric-specific problems that would limit the potential usefulness of Duloxetine to such patients. However, you should be aware that elderly patients are likely to be more sensitive to the effects the drug can have, compared to younger patients. Geriatric patients are more likely to suffer from low levels of sodium in the blood (known as hyponatremia). This means that the chance of experiencing falls is increased, so caution must be exercised.

As of writing, the exact effects of this drug on pregnant women is not clear. Your doctor will be most up to date with evolving studies and can determine whether or not this is a safe drug to take. However, if you become pregnant at all whilst taking Duloxetine, you should inform your doctor straight away, in case they wish to make any adjustments.

There is a similar case for women who are breastfeeding, as there are no appropriate studies that have been conducted into the effects this drug can have. You can weigh all potential risks and benefits with your doctor before making an informed decision as to whether this is the right drug to take.

In order to prevent any unwanted side effects, your doctor may likely schedule you in for regular appointment to check on your condition. It is important that you attend all such meetings.

If you have taken any of the following within the last 2 weeks, then you should not take Duloxetine.

  • Methylene blue injection

Also, within 5 days of stopping taking Duloxetine, do not begin taking an MAO inhibitor. Doing so could lead to confusion, extremely high blood pressure, restlessness, stomach agitation, severe convulsions, intestinal symptoms or sudden high body temperature.

If you are a teenager, then you may find that taking Duloxetine causes you to become irritable, agitated, or to display other abnormal behaviors. It could also lead to some become depressed and having suicidal thoughts. As well as this, others experience big increases in energy, get easily upset, find it difficult sleeping, or start to act recklessly. If you notice any of these signs at any time, then you should contact your doctor immediately. In particular, be clear to tell the doctor if you or anyone else in the family has tried to commit suicide or suffers from bipolar disorder.

Taking Duloxetine does have the potential to cause severe liver problems. Contact your doctor immediately if you experience any of the following.

  • Vomiting and nausea

Duloxetine can potentially cause neuroleptic malignant syndrome or serotonin syndrome. This can occur if you take it with any of the following drugs. If you do take any of them, then tell your doctor before using Duloxetine.

  • St. John's wort or some pain medicines (eg, tramadol [UltramĀ®]

Taking Duloxetine can increase your chance of experiencing bleeding problems. If you take any of the following drugs which thin the blood, then tell your doctor.

  • Warfarin (CoumadinĀ®).

You may also find you experience serious skin reactions. If you experience any of the following then ask your doctor for advice straight away.

  • Blistering, peeling, or loosening of the skin

If you suddenly stop taking Duloxetine, then this can lead to withdrawal symptoms such as vomiting, headaches, irritability, increased sweating, prickling or tingling feelings, dizziness, nausea or nightmares. For this reason, never immediately stop taking it. Instead, if your doctor asks you to stop, then follow their advice slowly decreasing your dosage.

Taking Duloxetine can have effects on your blood sugar levels. If you are diabetic, this can cause problems so, if you notice your blood sugar levels changing then you should speak to your doctor.

You may find that taking Duloxetine causes you to have blurred vision or to become dizzy. For this reason, you should not drive or perform any other dangerous tasks before you first know how the drug affects you personally. You may also find that you feel faint or lightheaded if you suddenly get up from sitting or lying. You should try to move slowly and, if the problem persists and it is worrying you, then contact your doctor for advice.

Before starting to take this medicine, and regularly throughout your treatment, you will need to test your blood pressure. Call your doctor right away if you notice any changes in your blood pressure.

Finally, when taking this drug you may experience hyponatremia, which is where the sodium levels in your blood become much lower. If, whilst taking this medicine, you experience memory problems or headaches, have difficulty concentrating, are unsteady, weak, or are confused, then you should contact our doctor and inform them.

Storage

You should store your Duloxetine in a sealed container as given to you when picking up your prescription. You should store it at room temperature, and keep it away from direct light, moisture, and heat. You should ever allow it to freeze, and never use it if it goes out of date at any time. Once you are done on your course of treatment, dispose of any leftover medication in a safe and sensible manner as advised by your doctor. You should ensure that your Duloxetine is kept safely away from children at all times, as it can be potentially harmful.

Summary

If you are suffering from depression, anxiety, fibromyalgia, long-lasting chronic pain, or diabetic peripheral neuropathy, then Duloxetine could be a very useful drug in helping to alleviate your symptoms. However, this is only the case if you take the medication in the exact dosages and frequency as instructed by your doctor. You should never take any more of the drug than prescribed, even if you see little difference in your condition. Instead, you should address any concerns to your doctor.

Above, you can find an extensive list of the art of side effects that can occur whilst taking this drug. If you are currently experiencing any of the more severe ones, or are worried about your condition, then contact your doctor immediately. They can advise you on the best way to stop these effects. Due to the possible effects this can have, you will be required to meet with your doctor at regular intervals to assess your condition. It is vital that you attend all such meetings, as your doctor can make any necessary adjustments so as to maximise the benefits you receive from taking this drug.