This information sheet answers some common questions patients ask about 3,4-Diaminopyridine (3,4-DAP). Further information can be found in the information leaflet supplied by the manufacturer or from your consultant neurologist, specialist nurse or pharmacist.

What is 3,4-Diaminonpyridine?

3,4-Diaminopyridine (3,4-DAP) is used in the treatment of Lambert-Eaton myasthenic syndrome (LEMS) and some congenital myasthenic syndromes (CMS). It is used to improve muscle strength.

Why Have I Been Prescribed This Medication?

3,4-DAP does not cure LEMS or CMS. It improves nerve-muscle transmission which helps to improve muscle strength.

How Does it Work?

3,4-DAP acts on the nerves allowing more of the chemical that stimulates muscle movement to be released.

How Long Does It Take To Work?

It takes about 30 to 60 minutes to start working after you have taken it.

What Dose Do I Take?

The dose is tailored to suit you. Do not take more than the prescribed dose as this may result in increased muscle weakness and also increase the risk of other potentially serious side effects.

How Do I Take It?

3,4-DAP comes in a tablet form of 20mg. You should always take the medicine as directed by your consultant neurologist.

  • Always read the information sheet provided by the manufacturer as well as this one, if possible. There may be additional information there that you could find useful
  • The tablets should be taken with food
  • You should take 3,4-DAP so that it can work when your muscles are needed most. For example, when you get up and about 30 to 60 minutes before meals. Never take more than the dose prescribed by your consultant neurologist. If you or someone else has taken an overdose of 3,4-DAP, contact your GP or go to the nearest A&E department immediately. Take the container with you if possible.

How Long Will I Be Taking It For?

The length of time you will be taking 3,4-DAP for depends on your needs. Do not stop taking your medication unless your consultant neurologist tells you to, even if you feel well.

Will 3,4-DAP Interfere With My Other Medications

There are no known significant interactions. It is safe to drink alcohol in moderation whilst taking 3,4-DAP.

Can Taking 3,4-DAP Cause Any Side Effects?

All medicines can cause unwanted side effects, which usually improve as your body adjusts to the new medicine. 3,4-DAP is usually very well tolerated. In the early weeks of treatment, 3,4-DAP may cause tingling around the mouth and in the fingers and toes, but this usually disappears about an hour after taking the drug. 3,4-DAP may rarely cause the following side effects:

  • Unsteadiness and tremor
  • Fatigue and sleeping difficulties
  • Anxiety
  • Blurred vision
  • Diarrhoea
  • Coughing
  • Coldness in the extremities
  • Irregular heart beat and palpitations
  • Producing more phlegm and saliva than usual

Please inform your neurologist or GP if you experience any of these side effects.

An overdose of 3,4-DAP can cause epileptic fits, but that is extremely unlikely at normal doses. However, caution may be needed in people who already have epilepsy. Certain heart conditions are also a contraindication to use. Theoretically, 3,4-DAP can exacerbate asthma and that possibility should be discussed before starting treatment.

Do I Need Any Special Checks Whilst On 3,4-DAP

There are no special checks required.

Is 3,4-DAP OK with Pregnancy and Breastfeeding

There is no evidence to suggest that 3,4-DAP is harmful during pregnancy or breastfeeding. However, if you are planning to become pregnant whilst taking 3,4-DAP, you should discuss this with your consultant neurologist.

More information on pregnancy and myasthenia can be found here.

Keep All medicines out of the reach of children

Never give any medication prescribed to you to anyone else