Article Date: 10/1/2009

Anti-Infectives And The Elderly
geriatric

Anti-Infectives And The Elderly

Taking into account systemic, physical and psychosocial issues can help these drugs bust the bugs.

RICHARD MARK KIRKNER, Pboenixville, Pa.

Because geriatric patients can have slightly different needs when taking anti-infective medications, it's important you be aware of the nuances of prescribing these drugs to this age group.

As a result, here, I discuss what you need to know when prescribing the various categories of anti-infective medications to this population, based on interviews with anti-infective experts. (See “Don't Forget Supportive Therapy”)

Don't Forget Supportive Therapy

The anti-infective experts interviewed for this article say I they've found supportive, non-prescriptive therapies can enhance the effectiveness of infection-fighting agents to the elderly eye.
For instance, Dr. Skorin recommends a three-point regimen for chronic blepharitis and meibomianitis.
“The safest thing to do is to instruct these patients to use warm compresses, lid scrubs and express their meibomian glands because you cannot keep them on topical antibiotic ointments indefinitely,” he says.
In the nursing home, nurses and aids take orders for commercial lid scrubs more seriously than homemade remedies, Dr. Eger says.
“Just writing 'baby shampoo' for lid scrubs seems like such an innocuous task or treatment,” he says. “I prescribe commercial products knowing that nurses and aids will adhere to my recommendations.”
Dr. Eger adds that he also prescribes artificial tears along with any therapy for ocular surface disease.
“They [artificial tears] lubricate the eye, wash away bacteria, help rinse the lids and prevent infection with very few side effects,” he says. “It's the simple things, but they offer the greatest relief,” he says.

Fluoroquinolones

Although this widely prescribed class of anti-infectives has few, if any side effects, researchers and clinicians have reported minor problems in elderly patients who take these drugs.

For instance, Noah Eger, O.D., who treats a number of nursing home patients in his Coraopolis, Pa. practice, cautions that fluoroquinolones have been linked to causing diplopia.1 This could worsen vision problems for an elderly patient who already has diplopia or nerve paralysis.

“I have a fair share of patients with diplopia in the nursing home, as well as 4th and 6th nerve palsies,” Dr. Eger says. “Prescribing a medication that can cause diplopia can make their cases more challenging.”

Also, some fluoroquinolones can interact with sulfonylureas, which diabetic patients use to control hypoglycemia, causing their glucose levels to drop quickly and inducing diabetic shock in rare cases, says optometrist Marc Myers, who practices at the Veterans Affairs Medical Center in Coatesville, Pa. Since much of the elderly population suffers from Type 2 diabetes, you must be aware of these drug interactions.

For his part, Dr. Myers says he uses the VAs EMR software as a back-up in identifying these interactions.

“If I type in a medication that has an interaction, I get a [red] flag right away,” he says. “Having a complete medical history along with a complete list of medications the patient is using is invaluable.”

Optometrist Andrew Gurwood, professor at the Pennsylvania College of Optometry, Salus University, who also practices at the Albert Einstein Medical Center in Philadelphia, says when a geriatric patient presents with an inflamed and painful ocular infection, he may prescribe non-fluoroquinolone combination drops rather than his typical stepwise approach of a fluoroquinolone with concomitant non-steroidal anti-inflammatory drugs (NSAIDS) or steroids.

His reason:

“Young patients can more easily administer the drops than elderly patients because their fingers are more able to squeeze the bottle,” he explains. “Also, workforce patients are more capable of affording two separate agents.”

If, however, Dr. Gurwood does opt for stepwise therapy in a geriatric patient, he says he starts the patient typically on a fluoroquinolone and then adds a second anti-inflammatory agent (corticosteroid or NSAID) once the infection is under control.

“I do this because I want the option of continuing the topical steroid or NSAID longer than the topical anti-infective,” he says.

This covers the inflammation without extending the antibiotic beyond seven to 10 days, as overuse of antibiotics contributes to bacterial resistance. Remember: The elderly population has been known to use more drops than needed.

With regard to resistance: Be sure to research the bacterial resistance rates of both the third and fourth generation fluoroquinolones prior to prescribing a specific drug to the elderly population, particularly in those who reside in healthcare centers, such as nursing homes. This is because methicillin-resistant Staphylococcus aureus (MRSA) — a gram-positive bacteria responsible for infections, such as pneumonia, cellulitis, bacteremia and wound infections, and ocular diseases, such as keratitis, endophthalmitis, Conjunctivitis and dacrocysti-tis — is often found in nursing homes, among other healthcare settings.

Aminoglycosides

This class of anti-infectives, like fluoroquinolones, also requires consideration with regard to the elderly population as a result of the possible presence of MRSA. Therefore, do your research to determine the MRSA-resistance rates of ophthalmic aminoglycosides (drops and ointment formulations) prior to writing a prescription to an elderly patient.

Also, regardless of which ophthalmic aminoglycoside you choose, be aware that the ointment versions can blur vision, which can be especially problematic for ambulatory nursing home patients. As a result, if one of these patients requires the additional coverage of an ointment, consider instructing him to use it only at bedtime, when he won't require vision, says Dr. Eger.

Antivirals

This anti-infective drug class is indicated for treating herpes zoster (known commonly as shingles) — something that has been prevalent in the geriatric population since the introduction of the varicella virus vaccine.

“If somebody comes in with herpes zoster ophthalmicus, you're obligated to start oral antiviral medications, especially if there is dermatome skin involvement,” says Leonid Skorin Jr., O.D., D.O., a Mayo Health System ophthalmologist in Albert Lea, Minn. To minimize the risk of ocular iritis, treatment should commence within 72 hours of onset, he says.

In addition, oral antiviral drugs are indicated for herpes simplex, although cases of simple dendritic herpetic keratitis typically require a topical antiviral medication, Dr. Skorin says.

Two caveats: While patients with chronic recurrent herpes simplex disease can usually tolerate topical antiviral medication, the elderly, with their compromised immune systems, are at increased risk of ocular toxicity from the drug; and topical agents will not treat stromal or uveitic inflammation secondary to the simplex virus. This merits a switch to a course of an oral antiviral drug.

Dr. Skorin says a patient in her 80s who recently presented reminded him just how challenging treating herpes zoster is in this age group. She had the classic shingles and iritis. Dr. Skorin says he started her on a topical corticosteroid to treat the iritis. However, that suppressed her immune response to the point that it reactivated her dormant herpes simplex, so he had to treat both her herpes zoster and herpes simplex.

“If you're treating herpes simplex, you shouldn't prescribe steroids unless the stroma becomes involved,” he says.

Unwilling to take the patient off the steroids out of concern the iritis would flare up, Dr. Skorin started the patient on a topical antiviral drug to cover the simplex virus. However, this resulted in corneal toxicity that affected her vision. Dr. Skorin says he was able to quiet the symptoms enough with topical antiviral therapy to put her on an oral antiviral medication with corticosteroid injections.

One benefit of oral antivirals is that patients who have chronic diseases, such as herpes zoster or herpes simplex, can use them for up to a year. They provide good coverage when topical antivirals cause corneal toxicity.

Prescribing oral anti-infectives

Perhaps the biggest challenge in prescribing oral anti-infectives, specifically antibiotics, to the geriatric patient is keeping abreast of potential drug interactions and side effects, says Dr. Eger.

“It's not uncommon to see a person on 20, 25 medications in the nursing home,” he notes.

“… I'm very cautious when prescribing oral medications for that reason alone.”

In addition, unlike their topical counterparts, oral antibiotics have an increased risk of causing gastrointestinal upset and nausea in elderly patients, Dr. Gurwood says.

Similar to their topical counterparts, however, oral antibiotics can pose a challenge for a geriatric patient's physical and mental limitations, he adds.

“You have to determine before prescribing a medication, can they [the patient] swallow the pill? Can they handle the pill? Can they see the pill? Since they may already be taking a bunch of other pills, you must consider their mental faculties,” Dr. Gurwood explains. “What if they get this new pill confused with the other pills?” (See “10 Pearls For Prescribing Anti-infectives in The Geriatric Patient”)

10 Pearls For Prescribing Anti-lnfentives in The Geriatric Patient

1. Look for the underlying cause, and target your treatment accordingly. The geriatric patient can have a host of comorbidities. “Correlating the constellation of ocular signs and symptoms in combination with a systemic review of systems will ensure the ophthalmic diagnosis is correct,” explains Dr. Gurwood.
2. Understand the difference between bacteriocidal and bacteriostatic. The former — the fluoroquinolones, aminoglycosides and penicilins — kill the bacteria. The latter inhibits bacterial growth but doesn't kill it. “My philosophy is, when there's bacteria, I want to eradicate it,” Dr. Eger says.
3. Understand the drug chemistry in relation to the patient's comorbidities. “In the elderly you have to take into account whether they have liver or kidney failure and whether the drugs you're prescribing are cleared in the liver or cleared through the kidneys,” says Dr. Skorin.
4. Write out the dose and time frame for medication use. Dr. Myers says he has seen many patients stop taking their medicine after four days despite his instructed seven-to-10 day course. “I go as far as writing out the dose and the time frame to take medicines, essentially writing up a schedule,” he says.
5. Explain, educate, repeat. Dr. Skorin says he first gives instructions to the patient, then has an intern or technician review them with the patient. “Patients may be intimidated to ask me a question because they know I'm in a hurry, and they feel they can take more of the other person's time,” he says.
6. With topical drugs, make sure the patient can apply them before you prescribe them. Have the patient demonstrate in your chair that he can get the drops in the eye, says Dr. Gurwood. Some patients cannot get drops in the eye because of hand tremors, arthritis or blepharochalasis.
7. Make sure the patient can get the drug(s). Ask the patient: “Can you get to a pharmacy?” If not, Dr. Gurwood phones the prescription in to a pharmacy that delivers. For patients who cannot afford their prescriptions, refer them to a drug manufacturer's prescription assistance program.
8. When in doubt, re-evaluate. “If the disease isn't responding, review the therapy or diagnosis or both,” suggests Dr. Gurwood. This may include culturing the infection. “If it [the medication(s)] doesn't work, the first question the corneal specialist is going to ask is, 'Did you culture that?'”
9. Have the patient bring in the medications at follow-up. This is an opportunity to check that the caps are on the correct bottles, says Dr. Skorin. “We've found patients were using everything correctly based on the color of the caps, but they put the caps back on the wrong bottles.” This is another chance to have the patient show you how he uses the drops. “That's when you pick up the errors,” Dr. Skorin says.
10. Never prescribe below the recommended dosing — and don't taper anti-infectives. Drug misuse, meaning the under dosing as well as the overdosing of anti-infectives, is a culprit of microbial resistance to drugs, and tapering drops equals under dosing, says optometrist Joseph Sowka, professor at the Nova Southeastern University College of Optometry in Fort Laud erdale, Fla. “Some doctors still believe antibiotics should be tapered as the patient gets better,” he says, “but that's just not the way we do it.”

Regardless of whether you prescribe a topical or oral anti-infective, remember that geriatric patients take longer to heal than young, healthy patients due to both an age-induced decrease in the effectiveness of their immune system and likely accompanying systemic disease, such as diabetes, hypertension or cardiovascular disease. As a result, frequent medication assessment is key to the successful management of these patients, says Dr. Gurwood. OM

  1. Fraunfelder FW, Fraunfelder FT. Diplopia and fluoroquinolones. Ophthalmology 2009; Sep;116(9):1814-7.
Mr. Kirkner is a medical editor and writer in suburban Philadelphia.


Optometric Management, Issue: October 2009