Outline and available formulations

Chloroquine is an antimalarial and antiparasitic medicine usually supplied as chloroquine phosphate. The phosphate salt contains the active chloroquine base; commonly stocked tablet strengths in the UK include 250 mg phosphate (around 155 mg base) and 500 mg phosphate (around 300 mg base).

The drug has a long history of use for prevention and treatment of malaria where the infecting Plasmodium species is sensitive. It may also be used for some forms of extraintestinal amebiasis, typically together with a luminal amebicide to clear intestinal carriage.

Widespread resistance of Plasmodium falciparum to chloroquine exists in many parts of the world. Before relying on chloroquine for prophylaxis or treatmentverify the information. up-to-date travel health guidance or seek specialist advice.

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Markers in medical practice

When the parasite is known or presumed to be susceptible, chloroquine may be appropriate for:

  • Treatment and weekly prevention of malaria caused by Plasmodium vivax, P. ovale and P. malariae, and certain P. falciparum strains that remain chloroquine-sensitive.
  • Systemic treatment of extraintestinal amebiasis, usually as part of a regimen that includes a luminal agent to eradicate intestinal carriage.

Because malaria susceptibility varies by country and region, consult destination-specific advice such as NHS Fit for Travel or a travel clinic before choosing an antimalarial.

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Administration protocol guidelines and if you forget to take a dose, here is some advice

Follow the directions provided by your prescriber or pharmacist. The following practical tips can help reduce negative health impacts and maintain adherence:

  • Take chloroquine with food or a milk drink if you experience stomach upset, unless your clinician advises otherwise.
  • Never exceed the prescribed dose or take doses more frequently than directed. Chloroquine deliberate overdose can be life threatening.
  • If you are using weekly prophylaxis, take the tablet on the same day each week to maintain consistent protection.
  • After leaving an area with malaria transmission, continue the recommended post-exposure prophylaxis period; see the dosing guideline section for usual durations.

Suppose you forget a dose and remember shortly afterwards, take it as soon as possible. If it is almost time for the next dose, skip the i skipped one dose and do not take a double dose to catch up.

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Dosing for malaria and amebiasis (guidance)

Many dosing tables and recommendations use chloroquine base as the reference. Typical conversions used in clinical practice are shown below:

  • 250 mg chloroquine phosphate is approximately 155 mg chloroquine base.
  • 500 mg chloroquine phosphate is approximately 300 mg chloroquine base.

Malaria prophylaxis regimen (weekly)

Adults: a common preventive regimen is 500 mg chloroquine phosphate (approximately 300 mg base) once weekly on a fixed day.

The infant and child population: give about 5 mg chloroquine base per kg body weight per week, not exceeding the adult weekly dose.

When possible start prophylaxis 1 to 2 weeks before entering a malarious area. For last-minute travel some clinicians use a single-day loading approach (for example 1 g phosphate on day 1 split into two doses about 6 hours apart), then continue weekly while exposed and for 4 to 8 weeks after leaving the area.

Treatment of acute chloroquine-susceptible malaria

An example adult three-day treatment course is:

  • Day 1: 1 g chloroquine phosphate (about 600 mg base) divided as an initial dose then 500 mg phosphate (about 300 mg base) after 6 to 8 hours.
  • Days 2 and 3: 500 mg chloroquine phosphate (about 300 mg base) once daily.

The typical adult total is about 2.5 g chloroquine phosphate (roughly 1.5 g base) given over three days.

Pediatric treatment is weight adjusted and should respect adult maximum single doses. One example schedule based on weight uses:

  • First dose: 10 mg base per kg (maximum around 600 mg base).
  • Second dose at 6 hours: 5 mg base per kg (maximum around 300 mg base).
  • Third dose at 24 hours: 5 mg base per kg.
  • Fourth dose at 36 hours: 5 mg base per kg.

Radical cure for vivax/ovale and extraintestinal amebiasis

For P. p or Plasmodium vivax. ovale infections, a hypnozoitocidal agent such as primaquine or tafenoquine is required to prevent relapse; always test for G6PD deficiency before prescribing these drugs.

For some forms of extraintestinal amebiasis an example adult regimen might be 1 g chloroquine phosphate once daily for 2 days followed by 500 mg once daily for 2 to 3 weeks, used together with a luminal agent such as diloxanide furoate or paromomycin to clear intestinal carriage.

Adjust doses for body weight, age, renal or hepatic impairment and other clinical factors as advised by your clinician. Local clinical guidance should take precedence.

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Online storage management helps organize and track items. and disposal procedures

  • Keep tablets in their original container at normal room temperature, protected from moisture and strong light.
  • Do not store medicines in the freezer. Keep all medicines out of the reach of children and animals.
  • Check expiry dates and do not use medication past the expiry. Return unwanted or out-of-date medicines to a pharmacy for safe disposal rather than putting them in household waste.

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Preventive safeguards, people engage through a series of social interactions. and time sensitive monitoring

Tell your prescriber or pharmacist about your full medical history and all medicines you take before starting chloroquine. Key considerations include existing eye disease, neuromuscular disorders, cardiac problems, blood disorders and any other prescribed or over-the-counter medicines.

  • Longer courses and higher cumulative doses require regular clinical review; tracking and monitoring of performance may include vision assessment, blood tests and evaluation of neuromuscular function.
  • Report any new visual symptoms promptly. Chloroquine-related retinopathy can be serious and may progress even after stopping treatment.
  • Avoid driving or operating machinery if you experience dizziness, drowsiness or visual disturbance.
  • Discuss alcohol, herbal remedies and other medicines with your clinician to identify potential the act of engaging in dialogues between people can shape outcomes..
  • Pregnancy: the choice of antimalarial in pregnancy depends on species, resistance patterns and gestational age; this should be decided by a clinician.

If your illness worsens or you do not start to recover within a few days of treatment, seek medical advice.

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Delayed effects, warning signs and fatal overdose

The likelihood and severity of harmful consequences depend on dose and duration of therapy. Short-term courses are generally better tolerated than long-term use. Visit an urgent care center for severe or worrying symptoms.

Urgent warning signs

  • Sudden or severe visual changes, eye pain or loss of vision.
  • Unexplained bleeding, bruising, very high fever or sore throat suggesting bone marrow suppression.
  • Seizure events, severe confusion or major behavioral changes.
  • Chest pain, severe muscle weakness, severe abdominal or back pain, or breathing difficulty.

Major undesirable health effects

  • Gastrointestinal upset including nausea, vomiting, abdominal discomfort and diarrhea.
  • Cranial pain, dizziness or temporary blurring of vision.
  • Skin itching or rash, reported more frequently in some populations.

Less typical and rare reactions

  • Skin changes, hair thinning, or rare pigment changes of skin, nails or oral mucosa.
  • Potential cardiac or neuromuscular effects with high doses or suffered an overdose.

Signs of overdose event

  • Marked drowsiness or severe agitation.
  • Serious cardiac or neurological compromise requiring emergency hospital treatment.

If secondary effects continue or cause concern, contact your healthcare professional for assessment and consideration of a different option therapy.

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Unconventional therapies and forecasted costs

The best antimalarial depends on your travel destination, local resistance patterns, medical history, pregnancy status and tolerance. Recurrent contingency options include:

  • Atovaquone/proguanil (for example Malarone or generic): often selected where chloroquine resistance is common; usually daily dosing.
  • Doxycycline: a daily preventive option; note the risk of photosensitivity and contrahints in certain groups.
  • Mefloquine (Lariam): weekly prophylaxis but may be unsuitable for people with a history of psychiatric or neurological disorders.
  • Artemisinin-based combination therapies (for example artemether-lumefantrine): standard treatment for uncomplicated falciparum malaria in many regions; used for treatment rather than prevention.
  • Primaquine and tafenoquine: used to prevent relapse of P. vivax and P. ovale infections; G6PD testing is mandatory before prescribing these drugs.
  • Hydroxychloroquine: a related compound mainly used for autoimmune conditions and not typically used for prophylaxis in areas of chloroquine resistance.

For intestinal amebiasis systemic options include metronidazole or tinidazole, usually followed by a luminal agent such as diloxanide furoate or paromomycin.

Typical retail price gradient in the UK (GBP)

Prices vary with brand, pack size, retailer and whether a private clinic consultation is charged. The following are approximate retail ranges in pounds sterling:

  • Chloroquine phosphate 250 mg, 20 tablets: approximately 8 to 12 pounds.
  • Chloroquine phosphate 500 mg, 20 tablets (if stocked): roughly 10 to 20 pounds.
  • Atovaquone/proguanil (course for short trip): around 25 to 45 pounds.
  • Doxycycline 100 mg for several weeks supply: about 10 to 25 pounds.
  • Mefloquine 250 mg course: typically 25 to 40 pounds.
  • Artemether-lumefantrine treatment pack: around 30 to 60 pounds.
  • Primaquine or tafenoquine courses: variable, often 20 to 60 pounds plus the cost of required G6PD testing (G6PD testing via private service may add roughly 20 to 50 pounds where applicable).

When buying online use UK-registered pharmacies that display General Pharmaceutical Council details. Private consultation or clinic fees may be charged in addition to the cost of medicines.

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Additional aspects about Chloroquine