Chapter 5 Implant-related drugs (Basic management of medication)
Professor of Department of Anesthesiology, School of Dental Medicine, Tsurumi UniversityHaruhisa Fukayama
I. Basic approach to medication
There are a number of drugs that can be used in implant treatment, but first it is necessary tounderstand basic pharmacology. The value of drug treatment lies in helping the living body to regain
homeostasis. However, it is also important to emphasize that the patient needs to take responsibility for
his/her own treatment.

II. Objectives of pharmacological therapy
Drugs are normally administered to treat the cause of a problem, symptomatically, or as a preventative
measure. For implant surgery, a variety of drugs are used with the intention of specific therapy,
symptomatic treatment, and prevention.

A. Causal therapy
This describes administration of antimicrobial drugs such as antibiotics and chemotherapeutic agents forpreventing the occurrence of postoperative infections.

B. Symptomatic treatment
This describes drug administration to improve disease symptoms, not treatment of the disease itself, as inA. above. In implant surgery, analgesic drugs are used for post-surgical pain, and anti-inflammatory
drugs are typically used to treat inflammation. Pain management is clearly an essential component of
implant surgery. Antihypertensive drugs that are used for intra-operative blood pressure control andemergency medicines given for unanticipated symptoms are also included in this category.

C. Preventive treatment
This describes administration of drugs to prevent onset of a disease. Generally speaking, it denotes theuse of disinfectants and antibiotics for infection control, and is often used for postoperative management
in implant surgery. Although not strictly speaking a drug treatment per say, local anesthesia isnevertheless an indispensable component of a smoothly conducted operation. Tranquilizers andintravenous anesthetics are given for intravenous sedation, and nitrous oxide and oxygen areadministered for inhalational sedation, for the same reason.

III. Routes of administration
Drugs are administered by several routes. Drugs that use the digestive tract and tongue to reach the bodyare known as enteral medicines, and are given orally or sublingually. Administrations of drugs byintravenous, subcutaneous, intrathecal, and intramuscular routes into the body are generally termed
injectable drugs. Application of drugs onto the skin, sprayed onto the digestive tract, or as eye drops ornasal sprays are termed topical medicines. Inhaled oxygen and nitrous oxide are also classed broadly as
external medicines.

A. Enteral drug administration
Administration via this route is simple and repetitive administration is possible, and the degree of pain1

felt by the patient is relatively low. This route of administration is the one most typically used for implant
surgery. A disadvantage of using this route is that an immediate effect cannot be expected. The rate ofabsorption is largely dependent on digestive tract function. Factors such as ingestion of food or
malfunctioning of the digestive organs can delay the entry of pharmacological agents into the blood
circulation. The drug might also be digested and become degraded along with food. Therefore it is possible
for the desired effect not to occur.

B. Injection
The effects of these drugs can manifest much faster and a pharmacological effect can be obtained with amuch lower dose than with enteral medicines. Using continuous intravenous infusion, a stable bloodconcentration can be maintained for a fixed period of time. Conversely, onset can be sudden, leading to
toxic levels. It is impossible to avoid the substantial pain caused by needles used in administering
medication by injection, and the instruments must be sterilized prior to use. Furthermore, injection has
the potential to result in infection, bleeding and tissue damage in the area of the needle. For implant
surgery, antimicrobials, intramuscular analgesics (IM), analgesics, minor tranquillizers, and anesthetics
are common drugs that are used intravenously. Technical skill is required for venous puncture.

C. External administration
Unlike injection, the major advantage of this method is freedom from pain. The medicinal effect iscontinuous, yet the treatment can be stopped if required, as undesirable effects appear. However, thisroute of administration cannot be used for those that require immediate treatment, and in some areas it
is difficult to predict when effects will be seen.
To obtain an analgesic effect from nitrous oxide/oxygen, an inhalation kit must be prepared, and thisrequires extra effort.
Each route of administration clearly has both advantages and disadvantages, and it is therefore vital touse these approaches with reference to the therapeutic objectives. The rate at which a drug enters theblood circulation is an important factor for its effectiveness. The intravenous route results in fastest onset
and because blood concentration can be controlled, is most reliable. This reliability is respectively lesswith drugs given by the intramuscular, subcutaneous, and oral routes. Rapid onset, however, can result inacute, severe onset of side effects and harmful effects, and therefore great caution must be taken.

IV. Pharmacological action
A. Local action
This describes the use of drugs that act at a specific location within the body. In implant surgery, drugs
that are applied locally for disinfection and sterilization, those used for conduction anesthesia, andhemostatic material used to control bleeding, are all classified under this category.

B. Systemic action
This is where the drug is absorbed from the site of application, and enters the circulation in order to exert
its effect on the tissues of the body. In implant surgery, antimicrobials, anti-inflammatory drugs, nitrous2

oxide and tranquilizers used for sedation come into this category.
It should be noted that these two actions are not separate, and that they act synergistically. A drug that
was administered for its local effects can also affect distant parts of the body, and the opposite is true. For
example,administrationofatypeofdisinfectant

canresult in

anaphylactic

shock,

andanti-inflammatories can cause a stomach ulcer. Bearing these considerations in mind, all of the effects ofeach drug have to be acknowledged and drugs should be administered with due caution.

V. Pharmacokinetics
The time it takes for a blood concentration to decrease by half is known as the elimination half-life of adrug. If this period is lengthened, the effect of the drug is prolonged; in contrast, if this period isshortened, the effect becomes shorter. There are several factors that influence drug half-life. Obesity,
hepatic disease, renal impairment and low cardiac output are factors that extend the elimination half-life.
As the excretory function in infants is not yet fully developed, they are therefore more sensitive to theeffects of drugs. In pregnancy, factors such as renal blood flow, cardiac output and blood plasma volumes
are raised, resulting in faster elimination of the drug from the blood circulation. In addition, many drugs
are able to pass through the placenta and thus reach the fetus. In the elderly, bodily functions such as
cardiac output, lung capacity, renal blood flow, and hepatic blood flow to name a few, become less efficientleading to lengthening of the elimination half-life, consequently prolonging the pharmacological effect ofdrugs.
It is not simple to assess each individual in order to predict the effect that a particular drug will have.
However, in implant surgery, it is important to evaluate the results of blood tests and the physicalexamination, so as to be able to administer adequate doses with the correct frequency, for each particularpatient.

VI. Drug side effects
All drugs have a main effect (used to treat a particular problem) and side effects (other effects). The
frequency of manifestation of the symptoms of side effects varies widely with factors such as, age, sex, thephysique of the patient, and the administered dose of the drug or concomitant use of other drugs. In
implant surgery, side effects that involve the digestive system are common, due to postoperative
administration of oral drugs.

VII. Medicines management
Under the Pharmaceutical Affairs Law, drugs are classed into poisons, dangerous drugs, and common
drugs, and their means of storage and management are specified. Furthermore, narcotics andpsychotropics are strictly controlled by the Narcotics and Psychotropics Control Act. The drugs used inimplant surgery should be stored and managed in accordance with their specific class. Management
should not only be according to the storage location, but also specifics such as the storage temperature,container, and whether the drug should be protected from light, as stated in the package insert.

3References
1)

Ogura H. Pharmacological action. Ogura H, Ogura Y eds. Contemporary dental pharmacology. Tokyo.

Ishiyaku Pub, Inc. 1980; 24. (in Japanese)2)

Lee C, Hamada S, Sakagami H, Shibata T, Nifuji A. Introduction. Sakagami H, Nifuji A, Hamada S,

Lee C eds. Dental pharmacology. Tokyo. Gakkennshoin Ltd. 2008; 1-50. (in Japanese)4