HOST MODULATION THERAPY - NOTES

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HOST MODULATION THERAPY - NOTES 

Host is defined as the organism from which the parasite derives its nourishment.
Modulation is defined as the alteration of function or status of something in response to a stimulus or an altered chemical or physical environment.

Williams and Golub et al  introduced the concept of host modulation to dentistry.


Basic concept behind host modulation:

Most of the destruction of periodontium is due to proinflammatory mediators of the host.

The main causes of this:

Matrix metalloproteinase - MMP 
- Host derived destructive enzyme
Cytokines and prostanoids 
- Causes changes in osteoclast activity.

Therefore, MMPs are the Primary target for host modulation therapy
Cytokines and Prostanoids are additional targets

Another target of HMT is to increase the protective or 
anti-inflammatory mediators.

Thus, the purpose of HMT is to restore the balance between destructive  pro-inflammatory and protective anti-inflammatory mediators.

HMT is considered an adjunctive treatment option for intervention in periodontal disease. It is Useful in susceptible, high risk hosts.


Drugs used in HMT

► Systemically administered drugs
 NSAIDs
They inhibit the production of prostaglandins - hence reduce tissue inflammation.
However disadvantages including GI, renal and hepatic problems - make it impossible to take NSAID on a long term basis.
Currently not employed in HMT

 Bisphosphonates
Bone seeking agents - inhibit bone resorption - disrupt osteoclast activity

 SDD - Sub - Antimicrobial-Dose Doxycycline

20 mg dose of doxycycline - used as an adjunct for SRP - Periostat.
Therapeutic effect - not anti-microbial , but by inhibition of MMP, cytokine and osteoclast activity.
It is the only systemically administered HMT - approved by US FDA and accepted by ADA.


► Locally administered Drugs

 NSAIDs

 topical ketorolac - not approved

 

 Enamel Matrix Proteins, Growth Factors, and Bone Morphogenetic Proteins 
Improve wound healing and stimulate regeneration

Locally administered HMTs currently approved - 

¯ Enamel matrix proteins ( Emdogain )
¯ Recombinant human platelet-derived growth factor -BB (GEM 21S)
¯ BMP-2 (INFUSE)

► Emerging options

 CMT 
Chemically modified Tetracycline - non antibiotic tetracycline analogs
  • CMT-3 and CMT-8 
Lack antibiotic activity but retain anti-MMP activity.
 
 Anti-cytokine drugs
TNF alpha antagonists - eg: Infliximab, Etanercept - currently used in treatment of rheumatoid arthritis. 
Yet to be approved for periodontal treatment.