Drotaverine Hydrochloride: Uses, Dose, Side Effects, Indications and Cost

Drotaverine is a relatively new synthetic pharmaceutical invention derived from benzylisoquinoline that belongs to the hydroisoquinolone class of drugs. It is an effective spasmolytic drug used in the symptomatic treatment of various conditions, such as gastrointestinal diseases, biliary dyskinesia and vasomotor diseases associated with smooth muscle spasms.

Drotaverine - a benzylisoquinoline derivative, works as an antispasmodic drug which inhibits phosphodiesterase-4 (PDE4). Drotaverine is structurally related to papaverine, although drotaverine displays more significant antispasmodic potential than papaverine.

Drotaverine hydrochloride is an antispasmodic durg, a pain relief medicine; used to treated and relieve smooth muscle spasms i.e. is seen in menstrual pain, abdominal pain, pain due to kidney stone and biliary stone and gastrointestinal colicky pain. 

Primarily drotaverine hydrochloride tablet is used to treat smooth muscle contractions which is felt as recurrent stomach pain in the gastrointestinal tract.

The patient is expected to follow all directions on the prescription label. 

• Drotaverine hydrochloride is not to be taken in either larger or smaller amounts or longer than prescribed.
• In case of any ambiguity, the patient is supposed to check with the doctor/pharmacist. 
• Usually, the prescription of drotaverine hydrochloride can be taken with a full glass of water.
• Store this medicine at room temperature, away from moisture, light and heat.
• In case of a missing dose on a therapeutic schedule, the missed dose must be taken as and when it was realised. 
• If the patient remembers the missed dose almost to the next scheduled dose time, it should not be taken as it could account for an overdose. 
• Extra medicine must never be taken to make up for the missed dose.
• Doctor consultation must be sought if the symptoms do not improve.
• In case of an overdose, the doctor must be consulted at once for medical attention.
• Do not use the drotaverine after the expiry date, which is printed on the carton.
  

Cyclic adenosine monophosphate (cAMP) is an important messenger in many biological processes. Once the cAMP gets activated, it participates in several pathways related to pain. PDE4 is an enzyme which can enhance the activation. By inhibiting PDE4, cAMP activation can be halted, leading to smooth muscle relaxation. Drotaverine does just that.

Drotaverine selectively inhibits PDE4, due to which the binding of cAMP and PDE4 is averted, thus relaxing the smooth muscles (mainly the gut).



Recent studies demonstrate that PDE4 inhibitors show potential as anticancer agents; nevertheless, research still has a long way to go. 

Drotaverine hydrochloride tablet has no cardiac toxic or hypotensive effects, which is why it can be prescribed to patients in the following conditions associated with coronary insufficiency and angina pectoris. 

• Gastric spasm 
• Intestinal spasm 
• Pyloric spasm (spasm at the pyloric sphincter situated at the bottom of the stomach)
• Cholelithiasis (gallstones which are formed from concentrated bile) 
• Spastic constipation 
• Tenesmus in dysentery (Tenesmus is the feeling of passing stools, even though the bowels are already empty)
• Dysmenorrhea (painful menstruation, typically associated with abdominal cramps) 
• Peripheral vascular disorders 

Tablets 

• In adult patients, 1–2 tablets of 40 mg are given thrice daily. 
• In children, drotaverine pediatric doses are to be provided according to age and body weight. 
• 1–6 years: ¼ to ½ tablet given once or twice depending on the intensity
• Over six years: ½ to 1 tablet given daily. 

Injection

• In adults, 2-4 ml injection may be given intramuscularly 1–3 times a day.
• No information about children's dosage. 

Almost all the adverse effects of drotaverine tablets come in the rare category, i.e., they are seen in >1/10,000 to<1/1,000 patients. 

• Gastrointestinal disorders - Rarely it can cause nausea and constipation.
• Nervous system disorders - Rarely can it cause headache, dizziness and insomnia?
• Cardiac disorders - Rarely it can cause palpitations and hypotension (low blood pressure)
• Immune system disorders - Rarely it can cause an allergic reaction (local skin swelling, hives, rash, itchy skin).

The patients are supposed to report to the doctor if they are experiencing any or all of the above or even any new adverse reactions which haven’t been listed. Doing so allows the assessment of the benefit/risk balance of the drug.

Drotaverine in pregnancy - Caution is to be advised when taking this drotaverine hydrochloride during pregnancy. The patient is supposed to inform the prescribing doctor about pregnancy or planning for one before using this drug.

Drotaverine in breastfeeding - Drotaverine hydrochloride use is not recommended while breastfeeding.

Driving and using machines - In general, the recommended doses of drotaverine hydrochloride do not influence the ability to drive and use machines. The patient is expected to individually assess the ability to drive/operate in case of side effects. In the case of dizziness, avoid driving or operating moving machinery.

An interaction is said to occur when the effects of the drug are changed by the presence of another drug, food, drink or by some environmental or chemical agent. The outcome can either be harmful (such as increasing the drug toxicity) or benedictory (such as a synergistic increase in outcome). The various interactions of drotaverine are:

• Isosorbide mononitrate - Isosorbide mononitrate belongs nitrates class of drugs and is given to treat angina (a type of chest pain due to the reduction in blood flow to heart muscles). When drotaverine tablets are given along with isosorbide mononitrate, an increase in vasodilatory activities is seen.
• Patent Blue - Patent Blue is a blue synthetic dye used in some parts of the world (in the European region) as a food colouring agent. In hospitals, Patent Blue is used in sentinel node biopsy and lymphangiography to colour lymph vessels before the patient is sent for imaging. When given with drotaverine tablets, it could reduce the effect of drotaverine.
• Riociguat - Riociguat belongs to the soluble guanylate cyclase (sGC) stimulators class of drugs used in adults to treat chronic thromboembolic pulmonary hypertension. When the combination of drotaverine tablets and riociguat is given, it may increase the hypotensive activities of riociguat.