Tufts OpenCourseware
Author: Michael Thompson, Ph.D.
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1. Introduction

When checking for a history of medications, the following history regarding medications should be asked for:

  1. Prescribed medications
  2. Over-the-counter (OTC) medications
    1. Cough/cold medications
    2. Diet pills
    3. Laxatives
    4. Herbal medications
  3. Recreational drugs: alcohol, cocaine, marijuana, etc.
  4. Drugs associated with allergies: aspirin, NSAIDs, sulfa drugs, penicillin, codeine, morphine and local anesthetics.
  5. Corticosteroid intake: is the patient currently on steroids or has the patient taken steroids for two weeks or longer within the past two years? — “The rule of two’s.”

2. Prescribed Medications

When a patient indicates he/she is taking prescribed medications you must use the Physician’s Desk Reference (PDR) and note if the patient’s medications will interact with the anesthetic, analgesics and antibiotics (AAAs) used in the dental setting.

3. OTC (Over-the-Counter) Medications

Diet pills, cough and cold medications contain sympathomimetic agents. These are sympathetic agents and act similar to epinephrine, a stimulant. They affect the heart and cause tachycardia and the patient feels extremely hyper. If the patient is known to be taking these agents, dental treatment should be deferred until the patient stops taking these agents, particularly if the cough and cold medications are being taken q6h (every 6 hours). You should only use anesthetics without epinephrine if postponement of treatment is not an option. Abuse of diet pills can cause these agents to synergize with the epinephrine in the local anesthetic (L.A.) and cause a sudden elevation of the BP (blood pressure). If the patient is on one or two diet pills a day, use of epinephrine in the L.A. is fine.

Vomiting, diarrhea, laxative abuse etc. can result in a loss of electrolytes. This loss can result in hypokalemia ( low potassium), hypochloremia (low chloride), hyponatremia (low sodium), metabolic alkalosis, etc. Potassium is a very important electrolyte in cardiac conduction. Normal levels for potassium in the blood are 3.5-5.0 mEq./dl. If potassium levels fall below this range, hypokalemic symptoms can clinically manifest. These include tingling/ numbness in hands and feet, muscle cramps/ weakness, irregular pulse, and cardiac arrythmia. Administration of any type of local anesthetic in the dental setting at this time can worsen this situation. A banana or orange juice can sometimes be given to alleviate the symptoms of hypokalemia and normal physiological potassium levels may be reached within 15-20 minutes in some situations.

Herbal medications can cause platelet dysfunction and consequent bleeding during surgery. Herbals need to be stopped 7 days prior to major surgery.

4. Recreational Drugs

Alcohol alters the potency of medications, e.g., anti-seizure medications, anti-depressants, etc. Cocaine will synergize with the epinephrine in the L.A., so do not use L.A. containing epinephrine in habitual cocaine abusers.

Ask patients if they have used any recreational drugs, injected any drugs, and if they have swapped needles during IV drug use.

Never be accusatory when asking drug-related questions. Also, let the patient know that the above-mentioned questions are asked of each and every patient coming to the dental clinic, and the information is confidential and critical for good care.

If you suspect that the patient may be affected by “high risk” behavior, ask the patient if he/she has been experiencing the following symptoms for some time (at least one to two months): tiredness, weakness, fatigue, chronic cough, night fever, night sweats, weight loss, loss of appetite, chronic diarrhea, and lymph glandular enlargements in the neck, axilla or abdomen. The patient suspects nothing. What you have elicited by this form of questioning is the presence or absence of AIDS-related symptoms and signs.

5. Anesthetics, Analgesics

5.1. Anesthetics

There are two distinct types of anesthetics: Amides and Esters.

5.1.1. Amides

Anesthetics belonging to this type are metabolized in the liver. Amides are the most commonly used local anesthetics in dentistry.

Amide local anesthetics are subdivided into two subtypes:

  1. Amides that contain epinephrine
  2. Amides that do not contain epinephrine

The amides that contain epinephrine are (i) Lidocaine,1:100,000 (ii) Prilocaine, 1:200,000 (iii) Bupivacaine, 1:200,000 or Septocaine, containing 1:100,000 or 1:200,000 epi.

Note: Lidocaine is the generic name. Lidocaine contains 1:100,000 epinephrine. Epinephrine is a sympathetic agent, having very good vasoconstrictor action. This action helps create a bloodless surgical field. Prilocaine contains 1:200,000 epinephrine. Thus Prilocaine contains less epinephrine than Lidocaine.

All amides containing epinephrine have bisulphites in them. These bisulphites are the oxidant preservatives to the epinephrine in the L.A. (local anesthetic). This information becomes significant in those patients who are allergic to sulfa drugs and consequently may sometimes be allergic to the amides containing epinephrine. Please note that not all patients allergic to sulfa drugs will be allergic to the amides containing epinephrine.

Mepivacaine is an amide that does not contain epinephrine. Lack of epinephrine in this L.A. makes the L.A. last for a shorter duration of time compared to Lidocaine or Prilocaine.

If a patient is allergic to the amides containing epinephrine, one can safely give the patient amides that do not contain epinephrine, as there is no cross reactivity within the families. Amides are less often associated with allergic reactions.

5.1.2. Esters

Esters are metabolized in the blood. They are highly cross-reactive, often associated with allergic reactions. It is for these reasons that esters are not commonly used in the dental environment. Cirrhosis of the liver (liver failure) is the only condition when esters are the preferred anesthetics, as they are metabolized in the blood. Propoxycaine isa member of the esters family, that is recommended for patients with cirrhosis.

5.2. Analgesics

Analgesics are pain killers. All analgesics are metabolized in the liver and are excreted through the kidneys.

Note: Do not prescribe analgesics for more than 2-2 ½ days so the patient’s situation can be reassessed if pain continues. It also decreases the chances for addiction, with the narcotics.

There are two main categories of analgesics:

5.2.1. Non-narcotic analgesics

  • Acetaminophen
  • Aspirin
  • NSAIDs (non-steroidal anti-inflammatory drugs), e.g. Ibuprofen

These drugs do not require a prescription to be dispensed. They are OTC (over-the-counter) drugs. Acetaminophen

Controls pain and fever. It has no anti-inflammatory action. It comes in two strengths:

  1. Regular Acetaminophen: 325 mg/tab.
  2. Extra Strength Acetaminophen: 500 mg/tab

Rx: (Prescribe) 2 tabs. q6h PRN, i.e., 2 tablets every 6 hours, as and when needed (PRN). Aspirin

Baby aspirin 81mg/tab; Adult aspirin 325 mg/tab.

Rx q6h PRN.

Note: Baby aspirin is usually taken once a day in patients with a past H/O (history of) thrombosis.

Aspirin and NSAIDS are prostaglandin inhibitors. They inhibit the vasodilator prostaglandins. Both of these agents are classified as anti-inflammatory: They help relieve pain, fever, and inflammation. These agents can irritate the gastric mucosal lining, causing bleeding in some cases, particularly if taken chronically and in large doses.

Aspirin and NSAIDS, if taken daily for extended periods, can affect the cohesiveness of the platelets. The affect of aspirin lasts for the entire life span of the platelets (which is 10-14 days). As aspirin permanently affects the platelets, patient’s physician must always be contacted prior to any major dental procedure. Consultation is necessary, for it is the M.D. who will decide if aspirin can be safely stopped prior to dental treatment or not. If clearance is given, aspirin is usually stopped 7 days prior to major dental procedures (gum surgery or extractions). If the patient is on high doses of aspirin, daily (1-2g/day or greater for arthritis), aspirin may have to be stopped 10 days prior to the surgical procedure.

Effect of aspirin is on the platelets, affecting primary homeostasis. BT (bleeding time) is prolonged. Platelet count is not affected. NSAIDS (non-steroidal anti-inflammatory drugs)

Example: Ibuprofen: 200mg/tab.

Rx 2 tabs. q6h PRN.

NSAIDs affect only the surface of the platelets. Affect on the platelets is temporary. Platelets regain their cohesiveness once the drug has been cleared completely. It is safe to say then, that NSAIDS can be stopped a day prior to the major surgical procedure, after consultation with the patient’s M.D.

Aspirin and NSAIDS are metabolized in the liver and excreted through the kidneys. They are contraindicated in both liver and kidney disease of any intensity.

5.2.2. Narcotic analgesics

These analgesics must be dispensed with a written prescription. You cannot call in the prescription over the telephone.

  • Opioids: Codeine, Morphine.
  • Opioid-like: Hydrocodone. Oxycodone. Meperidine. Propoxyphene.

Hydrocodone with Vicodin or Oxycodone with Acetaminophen is commonly used preparations in dentistry for moderate to severe pain. Codeine

Often used in the dental setting, in combination with Acetaminophen. The combination can dispensed in four different concentrations of codeine.

Acetaminophen + Codeine
#1 300 mg 7.5 mg
#2 300 mg 15 mg
#3 300 mg 30 mg
#4 300 mg 60 mg

Acetaminophen #3 is the most commonly prescribed preparation.

Rx 1 tab.q6h PRN

Codeine can cause allergies in some patients. A patient who is allergic to codeine will be allergic to morphine and vice-versa. There can be cross-reactivity.

In patients allergic to codeine and/or morphine, narcotic opioid-like agents can be prescribed like Acetaminophen and Hydrocodone or Acetaminophen and Oxycodone.

Percodan is Oxycodone with aspirin. As aspirin can promote bleeding, this combination is not advised for pain control in dentistry.

All aspirin and aspirin containing products, NSAIDS, Meperidine, Extra-strength Acetaminophen, Propoxyphene and Hydrocodone/Oxycodone with aspirin are contraindicated in renal disease.

Regular-strength Acetaminophen, Codeine, Hydrocodone and Acetaminophen are safe in renal disease patients.

6. Allergies

Always list drugs by name to check for allergies. The drugs evaluated for allergies are the drugs commonly associated with allergic reactions in the dental setting.

Anesthetics: Ask the patient if they have ever had a "shot in the mouth" or a L.A. before. If so, have they had any lightheadedness, dizziness, palpitations, etc.

Analgesics: Always ask the patient if they have received aspirin, NSAIDS, Codeine, or Morphine in the dental environment. These agents can cause allergic reactions. Have they had rash, nausea, dizziness, vomiting, etc. with any of these meds.

Codeine and morphine are given for severe pain. Find out if during hospitalization or major surgery were these potent pain killers given. Allergy to Codeine results in nausea, vomiting and light-headedness.

Aspirin and NSAIDs can also cause allergies. Both of these drugs are anti-inflammatory agents. If these agents cannot be used, then acetaminophen is the alternative drug. Acetaminophen does not cause allergic reactions.

Antibiotics: Regarding penicillin, always establish if the patient has had it more than once without any problems. Sulfa drugs are used to treat urinary tract infections (UTI) and lung infections. You check for allergy to sulfa drugs because the amide L.A. with epinephrine contain bisulphites in them. These bisulphites are the oxidant preservatives for the epinephrine. Sulpha allergy may occasionally occur with amide local anesthetic allergy. Please note that not all patients with allergy to sulfa drugs will have allergy to amide L.A. with epi. So in a new patient, you may do the following: Inject 0.25ml of the L.A. and observe local reaction (redness, swelling). If there is a local reaction, switch to carbocaine.

Diphenhydramine may be used as an alternative in patients with an H/O an allergic reaction to amides and to all L.A.s. A 1% diphenhydramine solution with 1:100,000 epi can be used as a L.A. (up to 3-4mls) per visit. Do not exceed 50 mg of Diphenhydramine per visit.

Allergic reactions occur a few minutes to a few hours after the agent has been administered. Acute reactions, which are rare, can occur within one hour of the agent being given, usually within the first five to ten minutes. Delayed reactions, which are more frequent and less severe, usually occur hours to days after the agent has been given.

Acute reactions are associated with the patient becoming very red in the face, restless and experiencing SOB due to a tightness in the chest caused by bronchoconstriction. The patient breaks out with hives, is itching all over, and is agitated. The eyes and nose are itchy and watery. The pulse is rapid and thready and the BP is falling. The above-mentioned symptoms and signs occur within a few seconds or minutes. The patient can throw a seizure and become unconscious. An emergency code should always be called.

The patient is placed in a horizontal position with the legs raised. The ABC’s and vital signs are constantly monitored. 0.3-0.5 ml of 1:1000 epinephrine is injected SC (subcutaneously) in the deltoid. Additionally the patient is given 4-6 L/min oxygen.

The epi will increase the BP and dilate the brochioles. This can be repeated 1-2 times per five mins. Once the patient is stabilized with epinephrine, the patient must be given Diphenhydramine 50 mg qid IM or IV (H1 blocker) and Cimetidine 300 mg qid IM or IV (H2 blocker) until fully out of danger. This management is performed by emergency personnel during the code management. For the next 2-3 days, 50 mg of Diphenhydramine and/or 300 mg Cimetidine PO qid is given to the patient once stabilized and discharged from the ER (emergency room).

6.1. Allergic Response

There are three levels of manifestations of an allergic response. A mild response is the most common. The patient will often call and report mild swelling, rash, and some itching after having left your office. A moderate response manifests with moderate swelling, a more pronounced rash, and itching. At any time during a mild or moderate manifestation, if the patient develops trouble breathing, they must go to the ER immediately. With mild and moderate reactions and no breathing difficulties, the patient can be treated with Cimetidine, 25 mg/tab. Instruct the patient to take 1 tab qid x 2-3 days for mild reactions and 50 mg qid x 2-3 days for moderate reactions. With severe reactions, we may lose a patient if management is not ASAP (as soon as possible). A severe reaction can arise within a few seconds to minutes after administering the allergy causing agent as discussed above.

Note: During an allergic response, mast cells release histamine which flows freely in the circulation and binds to the histamine receptors. Cimetidine prevents this binding, and with a 2-3 days administration of Diphenhydramine, the body is able to neutralize all of the released histamine. If this treatment is interrupted, then the histamine will still be circulating and possibly promote a reaction resulting in a drop in BP (blood pressure) and the consequent collapse of the patient.

Always inform the patient that when taking Cimetidine, drowsiness may result. They should not operate heavy machinery or drive a car during this time period. Legally we are obligated to inform all patients of this side effect and put a case note in the record indicating that we have informed the patient.

Non drowsy antihistamines that can be used instead, if the patient has to drive or work.

7. Corticosteroids

The daily secretion of glucocorticoids occurs in the early hours of the morning in all patients with normal functioning adrenal glands. ACTH, released by the pituitary gland, stimulates the adrenal cortex which in turn releases cortisol.

Normal mechanism:

adrenal cortex

If the patient takes steroids by mouth or by injection, the ACTH mechanism is inhibited, resulting in a consequent decrease in cortisol release.

Cortiscosteroids by mouth or injectionsACTH inhibition
Adrenal Cortex
Cortisol Release

Cortisol is an important hormone needed to fight stresses associated with infection, inflammation, bleeding, trauma, etc. Intake of steroids for two weeks or longer can inhibit ACTH release significantly. During extensive surgery (extractions, gum surgery, etc.), always consult with the patient’s physician to see if supplementation of steroids is needed prior to surgery. If you fail to supply the steroids when needed, the patient can collapse because of sudden, severe hypotension and hypoglycemia. This can become very life-threatening.

The steroid supplementation for routine major surgery is usually done in a "step-up/step-down" pattern. This therapy must be started 48 hours prior to the dental procedure. If the patient's M.D. states that the patient needs a total of 40 mg prednisone on the day of the surgery, then the following pattern for supplementation is followed:

48 hours prior to procedure dispense 10 mg; 24 hours prior to procedure dispense 20 mg prednisone; day of procedure 40 mg; 24 hours after procedure 20 mg; and 48 hours after procedure 10 mg. This is referred to as the "step-up/step-down" pattern.

10mg (2 days pre operative) 20mg (1 day pre op.) 40mg (day of surgery) 20mg (1 day post op.)10mg (2 days post operative)