SLIT Therapy

You or a family member may be starting treatment with oral allergy drops, also known as sublingual immunotherapy (SLIT). Recently, we have found that many people have similar questions concerning this treatment option, and this hand-out is designed to help answer many of those questions.


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Please feel free to speak with one of our staff members if your questions are not satisfactorily answered, or if new questions or problems arise. By working together on your treatment plan, we will have the best opportunity for good control of your allergy symptoms.

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Allergy immunotherapy is a type of preventative treatment for an allergic response to allergens such as pollen, mold, dust mites, and animal danders. Allergen immunotherapy treats the underlying cause of the allergic reaction, while medications such as antihistamines, nasal sprays, and asthma medications only treat the symptoms. Immunotherapy involves administering gradually increasing doses of the "causative allergen" to the allergic patient.

The gradual introduction of the allergen induces a natural immunity or tolerance to the allergen. This reduces the patient's allergic symptoms and lessons (and potentially eliminates) the need for medications.

Until recently, the only way to successfully administer allergen immunotherapy in the United States was by injections (allergy shots) at the doctor's office. Sublingual immunotherapy is now being introduced in the United States and is an injection-free procedure that offers patients the freedom to treat their allergies conveniently in their own home.
There are numerous advantages of sublingual immunotherapy:
  1. The patient does not have to experience repeated injections or the potential for discomfort of the upper arm at the injection site. Some people, especially children, have a fear of needles or shots. The needles used for allergy injections are tiny and are only given under the skin, but it is still a "shot".
  2. There is less potential for a systemic anaphylactic reaction, and there have been no reported fatalities from sublingual immunotherapy. Consequently, sublingual immunotherapy may thus be administered in the privacy and convenience of the patient's home.
  3. There is very little time commitment, as the treatment is administered once a day at home in a matter of minutes, eliminating the need for travel to the doctor's office and the 30 minute observation period that is required after allergy injections.
  4. For patients living a great distance from the doctor's office or for patients with difficult work schedules, sublingual immunotherapy offers the convenience of being able to administer the treatment wherever the patient happens to be.
There are several distinct disadvantages of sublingual immunotherapy:
  1. Although sublingual immunotherapy (SLIT) has been used in Europe for many years and currently accounts for more than half of all immunotherapy administered in the EU, it is still considered "investigational" and "off-label" in the United States and currently does not have FDA approval.
  2. Although the extracts used for sublingual immunotherapy are the same as those used for injection immunotherapy, the sublingual administration is considered "off-label" and is currently not covered by insurance plans. Therefore, the cost of sublingual immunotherapy, although comparable to the cost of allergy injections, is an entirely "out-of-pocket" expense, not reimbursable by insurance.
  3. Although sublingual immunotherapy has been shown to be quite effective, it may not quite be as efficacious as traditional allergy injections.
Our office uses sublingual immunotherapy for the treatment of respiratory allergies or allergic asthma secondary to airborne allergens such as trees, grasses, weeds, mold, dust mites, and animal dander.
Although treatment success varies from patient to patient, we anticipate improvement within the first few months of treatment. Maximum benefit may not be noted until one year of therapy has been completed. Adjustments to your dosing may be made when your extract vials are renewed. For that reason, it is important to keep our office informed about how you are responding to the treatment. Ninety percent of people improve on SLIT. If however, you do not improve with the first year's trial of SLIT, we would discuss stopping the sublingual drops.
David Scott, M.D. or William Scott, M.D. will take a medical history, complete physical examination, and then order specific allergy skin testing. Once the evaluation and testing are completed, specific treatment options will be discussed with you to guide you in your treatment decisions. If you choose to begin sublingual immunotherapy, your specific treatment kit will be prepared in our office, usually within two weeks. You will come to our office and take only the first oral dose and wait for 30 minutes of observation. You then take your treatment vials with you for administration of daily doses at home. Our office will provide you with complete dosing guidelines and renewal instructions. The staff will be available during routine office hours for phone advice concerning your sublingual immunotherapy.
There are no age restrictions for sublingual immunotherapy, although it is rare to begin any form of immunotherapy prior to the age of three.
There is an initial "build-up phase" that involves once-a-day dosing, beginning with one drop from a lower concentration and gradually increasing both the drop number and the allergy extract concentration over a period of 30 days. At the 30-day point, you will begin a once-a-day dosing regimen with 5 drops as the standard concentrated maintenance dose. This 5 drop-per-day dose will be continued for control of your allergies. The usual treatment course is 5 years, at which time reevaluation will be recommended. If you are doing well on maintenance immunotherapy, David Scott, M.D. or William Scott, M.D. will want to see you in clinic about every 6-12 months for a brief follow-up visit. The first year is a trial period. The drops will be continued only if you show significant improvement with your nasal allergies or allergic asthma (90% of patients).
The allergen extract is provided in convenient amber-glass bottles with a dropper mechanism that allows easy dosing under the tongue. Drops are placed under the tongue and held there for 2 minutes, then swallowed. We recommend no food or water for a period of 5 minutes after dosing. After that, there are no restrictions for eating or drinking. Also, there are no restrictions for eating and drinking prior to taking the drops. You can continue your routine allergy and asthma medications while on the drops. Over time with improvement you should need less medication. Do not stop your asthma medications without discussing this with our office first.
Due to the glycerin additive mixed with the extract, there is a slight sweet taste. However, since there are no taste buds under the tongue, most patients experience very little taste sensation.
The drops are taken once a day, every day, for 5 years. Treatment duration can vary from patient to patient, depending on the response to treatment and the need for continued symptom control.
See the dose adjustment schedule on the back page of the dosing log. In general, there will be no problem if you miss a day or two periodically. However, the best relief for your allergies will be experienced if you are taking the treatment each and every day. As with any preventative treatment, compliance is critical for success. The appropriate cumulative therapeutic benefits are best achieved if daily dosing is maintained.
The initial "build-up" treatment set will consist of three concentrations (3 or 6 vials, depending on if you need one or two prescriptions of different allergens in the extract of your particular prescription) and last approximately 7 weeks. Thereafter, the maintenance treatment bottle will be only the most concentrated strength.

Renewal prescriptions will be prepared and are designed to last approximately 2 months (2 vials if you are on a "single prescription" and 4 vials if you are on a "double prescription"). The most concentrated maintenance bottle is labeled 1:1 (red bottle). A 10 fold dilution of this is labeled 1:10 (yellow bottle). A further 10 fold dilution is labeled 1:100 (blue bottle) which is the weakest bottle that you will start treatment with.

As you complete the second week in your final bottle, 1:1 (red), you will fax (or mail) a copy of your dosing logs to our office along with pre-payment for your next 8 week supply of extract. The renewal treatment sets will be mailed to you within 2 weeks of receipt of your pre-payment and dosing logs. If you prefer, you can pick up your extract refill at our office. Please call ahead.
The treatment vials contain a glycerin preservative, which helps maintain stability even at room temperature, for a period of 8 weeks. You may keep the vial(s) you are currently using at room temperature, in a convenient location for dosing; however, you should keep the other vials refrigerated to insure maximum potency.
As with subcutaneous (injection) immunotherapy, we do not recommend that you receive sublingual immunotherapy if you are taking a beta-blocker medication (usually used for high blood pressure, as a migraine preventer, for cardiac problems, or glaucoma). If you are started on any new medication by a doctor and you are not sure what the medication is, please call our office and discuss this with one of our staff before taking any more sublingual immunotherapy.
Reported reactions to sublingual immunotherapy include itching of the tongue or lips (the most common reaction), gastrointestinal symptoms such as nausea and cramping and possible itchy hives on your skin. Systemic reactions have been reported and may include symptoms such as throat tightness or swelling, wheezing, a drop in blood pressure causing dizziness, fainting or collapse. These systemic reactions are extremely rare; there has never been a reported incidence of a fatal reaction to sublingual immunotherapy.

However, we recommend that you always have an oral antihistamine available for mild local reactions, as well as an epinephrine auto-injector (Epi-Pen) available for major systemic reactions on the way to the ER/911. These precautionary measures will be discussed with you at the time sublingual immunotherapy is initiated.

Patients may pay using cash, check, or credit card (Visa, MasterCard, or Discover), in advance of our mixing the allergy extract. The cost of one maintenance bottle, lasting one month is $124. If you receive a double prescription (2 bottles), the cost is $248. There is currently no insurance billing code for SLIT allergy extract and medical insurance will not help you with the cost.