Pentamidine

Pentamidine
Clinical data
Trade names Nebupent, Pentam, others[1]
AHFS/Drugs.com Monograph
Pregnancy
category
  • US: C (Risk not ruled out)
Routes of
administration		 IV, IM, inhalation
ATC code P01CX01 (WHO) QP51AF02 (WHO)
Legal status
Legal status
  • ℞ (Prescription only)
Pharmacokinetic data
Protein binding 69%
Biological half-life 6.4-9.4 hours
Identifiers
Synonyms pentamidine diisethionate, pentamidine dimesilate
CAS Number 100-33-4 YesY
PubChem (CID) 4735
DrugBank DB00738 YesY
ChemSpider 4573 YesY
UNII 673LC5J4LQ YesY
KEGG D08333 YesY
ChEBI CHEBI:45081 YesY
ChEMBL CHEMBL55 YesY
Chemical and physical data
Formula C19H24N4O2
Molar mass 340.42 g/mol
3D model (Jmol) Interactive image
  (verify)

Pentamidine is an antimicrobial medication used to treat African trypanosomiasis, leishmaniasis, babesiosis, and to prevent and treat pneumocystis pneumonia (PCP) in people with poor immune function. In African trypanosomiasis it is used for early disease before central nervous system involvement, as a second line option to suramin. It is an option for both visceral leishmaniasis and cutaneous leishmaniasis. Pentamidine can be given by injection into a vein or muscle or by inhalation.[1]

Common side effects of the injectable form include low blood sugar, pain at the site of injection, nausea, vomiting, low blood pressure, and kidney problems. Common side effects of the inhaled form include wheezing, cough, and nausea. It is unclear if doses should be changed in those with kidney or liver problems. Pentamidine is not recommended in early pregnancy but may be used in later pregnancy.[1] Its safety during breastfeeding is unclear.[2] While how the medication works is not entirely clear, it is beleived to involve decreasing the making of DNA, RNA, and protein.[1]

Pentamidine came into medical use in 1937.[3] It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system.[4] It is avaliable as a generic medication.[1] In the United States as of 2016 the inhalation powder costs 122.84 USD and a vial for injection costs 45.31 USD a dose.[5] Since it was found useful for PCP pneumonia the price has been increased greater than ten times.[3]

Medical uses

Other uses

Special Populations

Pregnancy

It has not been shown to cause birth defects in animal studies when given intravenously. There are no controlled studies to show if pentamidine can harm the fetus in pregnant women. It is only recommended if the drug of choice trimethoprim-sulfamethoxazole is contraindicated.[12]

Breastfeeding

There is no information regarding the excretion of pentamidine in breast milk, but since the adverse effects on breastfed infants are unknown currently, it is recommended by the manufacturer for the infant to not be breastfed or for the mother to stop the drug. Risks versus benefits for the mother should be considered when making this decision.[12]

Children

Pentamidine can be used in the prevention of PCP in children with HIV who cannot tolerate Trimethoprim/Sulfamethoxazole and can use a nebulizer. Intranvenous solutions of pentamidine should only be used in children with HIV older than 2 years old when other treatments are unavailable[13]

Elderly

There is not data for the use of pentamidine in this specific population.[12]

Contraindications

Side effects

Common

Rare

Others

Drug interactions

The additional or sequential use of other nephrotoxic drugs like aminoglycosides, amphotericin B, capreomycin, colistin, polymyxin B, vancomycin, foscarnet, or cisplatin should be closely monitored, or whenever possible completely avoided.[6]

Mechanism of action

The mechanism seems to vary with different organisms and is not well understood. However, pentamidine is suspected to work through various methods of interference of critical functions in DNA, RNA, phospholipid and protein synthesis.[6][15] Pentamidine binds to adenine-thymine-rich regions of the Trypanosoma parasite DNA, forming a cross-link between two adenines four to five base pairs apart. The drug also inhibits topoisomerase enzymes in the mitochondria of Pneumocystis jirovecii. Similarly, pentamidine inhibits type II topoisomerase in the mitochondria of the Trypanosoma parasite, resulting in breaks and unraveling it's circular mitochondrial DNA.[15]

Resistance

Strains of the Trypanosoma brucei parasite that are resistant to pentamidine have been discovered. Pentamidine is brought into the mitochondria through carriers, and the absence of these carriers prevents the drug from reaching its site of action.[15]

Pharmacokinetics

Absorption: Pentamidine is completely absorbed when given intravenously or intramuscularly. When inhaled through a nebulizer, pentamidine accumulates in the bronchoalveolar lavage fluid of the lungs at a higher concentration compared to injections. The inhaled form is minimally absorbed in the blood.[7] Absorption is unreliable when given orally.[8]

Distribution: When injected, pentamidine binds to tissues and proteins in the plasma. It accumulates in the kidney, liver, lungs, pancreas, spleen, and adrenal glands.[16] Additionally, pentamidine does not reach curative levels in the cerebrospinal fluid.[8] It has a volume of distribution of 286-1356 liters when given intravenously and 1658-3790 liters when given intramuscularly.[17] Inhaled pentamidine is mainly deposited into the bronchoalveolar lavage fluid of the lungs.[16]

Metabolism: Pentamidine is primarily metabolized by Cytochrome P450 enzymes in the liver.[17][18] Up to 12% of pentamidine is eliminated in the urine unchanged.[6]

Elimination: Pentamidine has an average half-life of 5–8 hours when given intravenously and 7–11 hours when given intramuscularly. However, these may increase with severe kidney problems.[16] Pentamidine can remain in the system for as long as 8 months after the first injection.[15]

Chemistry

Pentamidine isethionate for injection is commercially available as a lypophilized, white crystalline powder for reconstitution with sterile water or 5% Dextrose. After reconstitution, the mixture should be free from discoloration and precipitation. Reconstitution with sodium chloride should be avoided due to formation of precipitates. Intravenous solutions of pentamidine can be mixed with intravenous HIV medications like zidovidine and intravenous heart medications like diltiazem. However, intravenous solutions of antiviral foscarnet and antifungal fluconazole are incompatible with pentamidine.[6] To avoid side-effects associated with intravenous administration, the solution should be slowly infused to minimize the release of histamine.[15]

History

Pentamidine was first used to treat African trypanosomiasis in 1937 and leishmaniasis in 1940 before it was registered as pentamidine mesylate in 1950. Its efficacy against Pneumocystis jirovecii was demonstrated in 1987, following its re-emergence on the drug market in 1984 in the current isethionate form.[8]

Trade names and dose form

For oral inhalation and for nebulizer use:[5]

For intravenous and intramuscular use:[5]

See also

References

  1. 1 2 3 4 5 "Pentamidine Isethionate". The American Society of Health-System Pharmacists. Retrieved 3 December 2016.
  2. ↑ "Pentamidine Use During Pregnancy". www.drugs.com. Retrieved 3 December 2016.
  3. 1 2 Magill, Alan J.; Strickland, G. Thomas; Maguire, James H.; Ryan, Edward T.; Solomon, Tom (2012). Hunter's Tropical Medicine and Emerging Infectious Disease (9 ed.). Elsevier Health Sciences. p. 723. ISBN 1455740438.
  4. ↑ "WHO Model List of EssentialMedicines" (PDF). World Health Organization. October 2013. Retrieved 22 April 2014.
  5. 1 2 3 4 DrugBank, ed. (2016-08-17). "Pentamidine". DrugBank.
  6. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 "DailyMed - PENTAM 300- pentamidine isethionate injection, powder, lyophilized, for solution". dailymed.nlm.nih.gov. Retrieved 2016-11-07.
  7. 1 2 "DailyMed - NEBUPENT- pentamidine isethionate inhalant". dailymed.nlm.nih.gov. Retrieved 2016-11-07.
  8. 1 2 3 4 5 "Drugs". World Health Organization. Retrieved 2016-11-04.
  9. ↑ "Drugs@FDA: FDA Approved Drug Products". www.accessdata.fda.gov. Retrieved 2016-11-07.
  10. ↑ Lee MS, Johansen L, Zhang Y, et al. (December 2007). "The novel combination of chlorpromazine and pentamidine exerts synergistic antiproliferative effects through dual mitotic action". Cancer Res. 67 (23): 11359–67. doi:10.1158/0008-5472.CAN-07-2235. PMID 18056463.
  11. ↑ Penumutchu, Srinivasa R.; Chou, Ruey-Hwang; Yu, Chin (2014-08-01). "Structural Insights into Calcium-Bound S100P and the V Domain of the RAGE Complex". PLOS ONE. 9 (8): e103947. doi:10.1371/journal.pone.0103947. ISSN 1932-6203. PMC 4118983Freely accessible. PMID 25084534.
  12. 1 2 3 "Pentamidine Use During Pregnancy | Drugs.com". www.drugs.com. Retrieved 2016-11-10.
  13. ↑ "Pneumocystis jirovecii Pneumonia | Pediatric OI Prevention and Treatment Guidelines | AIDSinfo". AIDSinfo. Retrieved 2016-11-07.
  14. 1 2 3 "Pentamidine Side Effects in Detail - Drugs.com". www.drugs.com. Retrieved 2016-11-04.
  15. 1 2 3 4 5 Lemke, Thomas L.; Williams, David A., eds. (2013). Foye's Principles of Medicinal Chemistry (Seventh ed.). Philadelphia, PA: Lippincott Williams & Wilkins. ISBN 9781609133450.
  16. 1 2 3 "Pentamidine (Oral Inhalation) (Professional Patient Advice) - Drugs.com". www.drugs.com. Retrieved 2016-11-04.
  17. 1 2 "NebuPent, Pentam (pentamidine) dosing, indications, interactions, adverse effects, and more". reference.medscape.com. Retrieved 2016-11-06.
  18. ↑ Pubchem. "pentamidine | C19H24N4O2 - PubChem". pubchem.ncbi.nlm.nih.gov. Retrieved 2016-11-06.
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